diff --git a/.circleci/config.yml b/.circleci/config.yml
index a978278455218..4e9d85cd8ddde 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -107,8 +107,7 @@ jobs:
       - run:
           command: |
             mkdir -p ./build/__test_utils__
-            node ./scripts/print-warnings/print-warnings.js > build/WARNINGS
-            node ./scripts/print-warnings/print-warnings.js --js > build/__test_utils__/ReactAllWarnings.js
+            node ./scripts/print-warnings/print-warnings.js > build/__test_utils__/ReactAllWarnings.js
       - persist_to_workspace:
           root: .
           paths:
diff --git a/.github/workflows/commit_artifacts.yml b/.github/workflows/commit_artifacts.yml
index 2e5007982b1cb..db72ecf2df005 100644
--- a/.github/workflows/commit_artifacts.yml
+++ b/.github/workflows/commit_artifacts.yml
@@ -119,25 +119,24 @@ jobs:
             build/oss-experimental/react-refresh/cjs/react-refresh-babel.development.js
       - name: Move relevant files for React in www into compiled
         run: |
-          mkdir -p ./compiled
-          mkdir -p ./compiled/facebook-www
-          mkdir -p ./compiled/babel-plugin-react-refresh
-
-          # Copy the facebook-www folder into compiled
+          # Move the facebook-www folder into compiled
+          mkdir ./compiled
           mv build/facebook-www ./compiled
 
-          # Copy WARNINGS to facebook-www
-          mv build/WARNINGS ./compiled/facebook-www/WARNINGS
+          # Move ReactAllWarnings.js to facebook-www
+          mkdir ./compiled/facebook-www/__test_utils__
+          mv build/__test_utils__/ReactAllWarnings.js ./compiled/facebook-www/__test_utils__/ReactAllWarnings.js
 
-          # Copy eslint-plugin-react-hooks into facebook-www
+          # Move eslint-plugin-react-hooks into facebook-www
           mv build/oss-experimental/eslint-plugin-react-hooks/cjs/eslint-plugin-react-hooks.development.js \
             ./compiled/facebook-www/eslint-plugin-react-hooks.js
 
-          # Copy unstable_server-external-runtime.js into facebook-www
+          # Move unstable_server-external-runtime.js into facebook-www
           mv build/oss-stable/react-dom/unstable_server-external-runtime.js \
             ./compiled/facebook-www/unstable_server-external-runtime.js
 
-          # Copy react-refresh-babel.development.js into babel-plugin-react-refresh
+          # Move react-refresh-babel.development.js into babel-plugin-react-refresh
+          mkdir ./compiled/babel-plugin-react-refresh
           mv build/oss-experimental/react-refresh/cjs/react-refresh-babel.development.js \
             ./compiled/babel-plugin-react-refresh/index.js
 
diff --git a/fixtures/dom/src/__tests__/nested-act-test.js b/fixtures/dom/src/__tests__/nested-act-test.js
index d57bef7310e41..4a4c63eaad105 100644
--- a/fixtures/dom/src/__tests__/nested-act-test.js
+++ b/fixtures/dom/src/__tests__/nested-act-test.js
@@ -20,7 +20,7 @@ describe('unmocked scheduler', () => {
   beforeEach(() => {
     jest.resetModules();
     React = require('react');
-    DOMAct = require('react-dom/test-utils').act;
+    DOMAct = React.unstable_act;
     TestRenderer = require('react-test-renderer');
     TestAct = TestRenderer.act;
   });
@@ -61,7 +61,7 @@ describe('mocked scheduler', () => {
       require.requireActual('scheduler/unstable_mock')
     );
     React = require('react');
-    DOMAct = require('react-dom/test-utils').act;
+    DOMAct = React.unstable_act;
     TestRenderer = require('react-test-renderer');
     TestAct = TestRenderer.act;
   });
diff --git a/packages/react-cache/src/__tests__/ReactCacheOld-test.internal.js b/packages/react-cache/src/__tests__/ReactCacheOld-test.internal.js
index 9463b72e14a69..2403d2de286b1 100644
--- a/packages/react-cache/src/__tests__/ReactCacheOld-test.internal.js
+++ b/packages/react-cache/src/__tests__/ReactCacheOld-test.internal.js
@@ -121,7 +121,7 @@ describe('ReactCache', () => {
     }
 
     ReactTestRenderer.create(<App />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Suspend! [Hi]', 'Loading...']);
@@ -141,7 +141,7 @@ describe('ReactCache', () => {
     }
 
     const root = ReactTestRenderer.create(<App />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Suspend! [Hi]', 'Loading...']);
@@ -181,7 +181,7 @@ describe('ReactCache', () => {
         <App />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -210,7 +210,7 @@ describe('ReactCache', () => {
         <AsyncText ms={100} text={3} />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Suspend! [1]', 'Loading...']);
@@ -298,7 +298,7 @@ describe('ReactCache', () => {
         <App />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -356,7 +356,7 @@ describe('ReactCache', () => {
         <BadAsyncText text="Hi" />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -372,7 +372,7 @@ describe('ReactCache', () => {
         <BadAsyncText text="Hi" />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
diff --git a/packages/react-debug-tools/src/__tests__/ReactDevToolsHooksIntegration-test.js b/packages/react-debug-tools/src/__tests__/ReactDevToolsHooksIntegration-test.js
index 5da6b8de2a42e..eabcbd215bfb2 100644
--- a/packages/react-debug-tools/src/__tests__/ReactDevToolsHooksIntegration-test.js
+++ b/packages/react-debug-tools/src/__tests__/ReactDevToolsHooksIntegration-test.js
@@ -254,7 +254,7 @@ describe('React hooks DevTools integration', () => {
             <MyComponent />
           </React.Suspense>
         </div>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
 
diff --git a/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js b/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js
index 891e4f3e73834..cba7b3b2e7b61 100644
--- a/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js
+++ b/packages/react-devtools-shared/src/__tests__/inspectedElement-test.js
@@ -75,7 +75,7 @@ describe('InspectedElement', () => {
     // Used by inspectElementAtIndex() helper function
     utils.act(() => {
       testRendererInstance = TestRenderer.create(null, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -307,7 +307,7 @@ describe('InspectedElement', () => {
         ['An update to %s inside a test was not wrapped in act'],
         () => {
           testRendererInstance = TestRenderer.create(null, {
-            unstable_isConcurrent: true,
+            isConcurrent: true,
           });
         },
       );
@@ -469,7 +469,7 @@ describe('InspectedElement', () => {
       ['An update to %s inside a test was not wrapped in act'],
       () => {
         testRendererInstance = TestRenderer.create(null, {
-          unstable_isConcurrent: true,
+          isConcurrent: true,
         });
       },
     );
@@ -2034,7 +2034,7 @@ describe('InspectedElement', () => {
       ['An update to %s inside a test was not wrapped in act'],
       () => {
         testRendererInstance = TestRenderer.create(null, {
-          unstable_isConcurrent: true,
+          isConcurrent: true,
         });
       },
     );
@@ -2317,7 +2317,7 @@ describe('InspectedElement', () => {
               <Suspender target={id} />
             </React.Suspense>
           </Contexts>,
-          {unstable_isConcurrent: true},
+          {isConcurrent: true},
         );
       }, false);
       await utils.actAsync(() => {
@@ -2817,7 +2817,7 @@ describe('InspectedElement', () => {
           ['An update to %s inside a test was not wrapped in act'],
           () => {
             testRendererInstance = TestRenderer.create(null, {
-              unstable_isConcurrent: true,
+              isConcurrent: true,
             });
           },
         );
diff --git a/packages/react-devtools-shared/src/__tests__/utils.js b/packages/react-devtools-shared/src/__tests__/utils.js
index 0c5a0b09f7d01..bf5a8b98eab23 100644
--- a/packages/react-devtools-shared/src/__tests__/utils.js
+++ b/packages/react-devtools-shared/src/__tests__/utils.js
@@ -19,7 +19,7 @@ export function act(
   recursivelyFlush: boolean = true,
 ): void {
   const {act: actTestRenderer} = require('react-test-renderer');
-  const {act: actDOM} = require('react-dom/test-utils');
+  const actDOM = require('react').unstable_act;
 
   actDOM(() => {
     actTestRenderer(() => {
@@ -44,7 +44,7 @@ export async function actAsync(
   recursivelyFlush: boolean = true,
 ): Promise<void> {
   const {act: actTestRenderer} = require('react-test-renderer');
-  const {act: actDOM} = require('react-dom/test-utils');
+  const actDOM = require('react').unstable_act;
 
   await actDOM(async () => {
     await actTestRenderer(async () => {
diff --git a/packages/react-dom/src/__tests__/ReactDOMHydrationDiff-test.js b/packages/react-dom/src/__tests__/ReactDOMHydrationDiff-test.js
index 3bdcd9c16a966..45de6fa9104f4 100644
--- a/packages/react-dom/src/__tests__/ReactDOMHydrationDiff-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMHydrationDiff-test.js
@@ -25,7 +25,7 @@ describe('ReactDOMServerHydration', () => {
     React = require('react');
     ReactDOMClient = require('react-dom/client');
     ReactDOMServer = require('react-dom/server');
-    act = require('react-dom/test-utils').act;
+    act = React.unstable_act;
 
     console.error = jest.fn();
     container = document.createElement('div');
diff --git a/packages/react-dom/src/__tests__/ReactDOMInput-test.js b/packages/react-dom/src/__tests__/ReactDOMInput-test.js
index be4b59ce0806e..6b8baaddbe023 100644
--- a/packages/react-dom/src/__tests__/ReactDOMInput-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMInput-test.js
@@ -110,7 +110,10 @@ describe('ReactDOMInput', () => {
     expect(() => {
       ReactDOM.render(<input type="text" value={0} />, container);
     }).toErrorDev(
-      'Warning: You provided a `value` prop to a form field without an `onChange` handler.',
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
     );
   });
 
@@ -118,7 +121,10 @@ describe('ReactDOMInput', () => {
     expect(() => {
       ReactDOM.render(<input type="text" value="" />, container);
     }).toErrorDev(
-      'Warning: You provided a `value` prop to a form field without an `onChange` handler.',
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
     );
   });
 
@@ -126,7 +132,10 @@ describe('ReactDOMInput', () => {
     expect(() => {
       ReactDOM.render(<input type="text" value="0" />, container);
     }).toErrorDev(
-      'Warning: You provided a `value` prop to a form field without an `onChange` handler.',
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
     );
   });
 
diff --git a/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js b/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js
index 39a1bac1e9ede..810452c64a313 100644
--- a/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js
+++ b/packages/react-dom/src/__tests__/ReactDOMTextarea-test.js
@@ -759,4 +759,85 @@ describe('ReactDOMTextarea', () => {
     ReactDOM.render(<textarea defaultValue={null} />, container);
     expect(node.defaultValue).toBe('');
   });
+
+  it('should not warn about missing onChange if value is not set', () => {
+    expect(() => {
+      ReactTestUtils.renderIntoDocument(<textarea />);
+    }).not.toThrow();
+  });
+
+  it('should not warn about missing onChange if value is undefined', () => {
+    expect(() => {
+      ReactTestUtils.renderIntoDocument(<textarea value={undefined} />);
+    }).not.toThrow();
+  });
+
+  it('should not warn about missing onChange if onChange is set', () => {
+    expect(() => {
+      const change = jest.fn();
+      ReactTestUtils.renderIntoDocument(
+        <textarea value="something" onChange={change} />,
+      );
+    }).not.toThrow();
+  });
+
+  it('should not warn about missing onChange if disabled is true', () => {
+    expect(() => {
+      ReactTestUtils.renderIntoDocument(
+        <textarea value="something" disabled={true} />,
+      );
+    }).not.toThrow();
+  });
+
+  it('should not warn about missing onChange if value is not set', () => {
+    expect(() => {
+      ReactTestUtils.renderIntoDocument(
+        <textarea value="something" readOnly={true} />,
+      );
+    }).not.toThrow();
+  });
+
+  it('should warn about missing onChange if value is false', () => {
+    expect(() =>
+      ReactTestUtils.renderIntoDocument(<textarea value={false} />),
+    ).toErrorDev(
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
+    );
+  });
+
+  it('should warn about missing onChange if value is 0', () => {
+    expect(() =>
+      ReactTestUtils.renderIntoDocument(<textarea value={0} />),
+    ).toErrorDev(
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
+    );
+  });
+
+  it('should warn about missing onChange if value is "0"', () => {
+    expect(() =>
+      ReactTestUtils.renderIntoDocument(<textarea value="0" />),
+    ).toErrorDev(
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
+    );
+  });
+
+  it('should warn about missing onChange if value is ""', () => {
+    expect(() =>
+      ReactTestUtils.renderIntoDocument(<textarea value="" />),
+    ).toErrorDev(
+      'Warning: You provided a `value` prop to a form ' +
+        'field without an `onChange` handler. This will render a read-only ' +
+        'field. If the field should be mutable use `defaultValue`. ' +
+        'Otherwise, set either `onChange` or `readOnly`.',
+    );
+  });
 });
diff --git a/packages/react-dom/src/__tests__/ReactTestUtilsActUnmockedScheduler-test.js b/packages/react-dom/src/__tests__/ReactTestUtilsActUnmockedScheduler-test.js
index e0bce1c01ca69..a38d4c0698ced 100644
--- a/packages/react-dom/src/__tests__/ReactTestUtilsActUnmockedScheduler-test.js
+++ b/packages/react-dom/src/__tests__/ReactTestUtilsActUnmockedScheduler-test.js
@@ -37,7 +37,7 @@ beforeEach(() => {
   yields = [];
   React = require('react');
   ReactDOM = require('react-dom');
-  act = require('react-dom/test-utils').act;
+  act = React.unstable_act;
   container = document.createElement('div');
   document.body.appendChild(container);
 });
diff --git a/packages/react-reconciler/src/ReactFiberLane.js b/packages/react-reconciler/src/ReactFiberLane.js
index 905eda36a93e8..7e056f2e71068 100644
--- a/packages/react-reconciler/src/ReactFiberLane.js
+++ b/packages/react-reconciler/src/ReactFiberLane.js
@@ -25,6 +25,9 @@ import {
   enableTransitionTracing,
   enableUnifiedSyncLane,
   enableUpdaterTracking,
+  syncLaneExpirationMs,
+  transitionLaneExpirationMs,
+  retryLaneExpirationMs,
 } from 'shared/ReactFeatureFlags';
 import {isDevToolsPresent} from './ReactFiberDevToolsHook';
 import {ConcurrentUpdatesByDefaultMode, NoMode} from './ReactTypeOfMode';
@@ -355,7 +358,7 @@ function computeExpirationTime(lane: Lane, currentTime: number) {
       // to fix the starvation. However, this scenario supports the idea that
       // expiration times are an important safeguard when starvation
       // does happen.
-      return currentTime + 250;
+      return currentTime + syncLaneExpirationMs;
     case DefaultHydrationLane:
     case DefaultLane:
     case TransitionHydrationLane:
@@ -374,7 +377,7 @@ function computeExpirationTime(lane: Lane, currentTime: number) {
     case TransitionLane13:
     case TransitionLane14:
     case TransitionLane15:
-      return currentTime + 5000;
+      return currentTime + transitionLaneExpirationMs;
     case RetryLane1:
     case RetryLane2:
     case RetryLane3:
@@ -384,7 +387,9 @@ function computeExpirationTime(lane: Lane, currentTime: number) {
       // crashes. There must be some other underlying bug; not super urgent but
       // ideally should figure out why and fix it. Unfortunately we don't have
       // a repro for the crashes, only detected via production metrics.
-      return enableRetryLaneExpiration ? currentTime + 5000 : NoTimestamp;
+      return enableRetryLaneExpiration
+        ? currentTime + retryLaneExpirationMs
+        : NoTimestamp;
     case SelectiveHydrationLane:
     case IdleHydrationLane:
     case IdleLane:
@@ -423,7 +428,9 @@ export function markStarvedLanesAsExpired(
   // We exclude retry lanes because those must always be time sliced, in order
   // to unwrap uncached promises.
   // TODO: Write a test for this
-  let lanes = pendingLanes & ~RetryLanes;
+  let lanes = enableRetryLaneExpiration
+    ? pendingLanes
+    : pendingLanes & ~RetryLanes;
   while (lanes > 0) {
     const index = pickArbitraryLaneIndex(lanes);
     const lane = 1 << index;
diff --git a/packages/react-reconciler/src/__tests__/DebugTracing-test.internal.js b/packages/react-reconciler/src/__tests__/DebugTracing-test.internal.js
index f8026d6ea9fab..041086690e7fe 100644
--- a/packages/react-reconciler/src/__tests__/DebugTracing-test.internal.js
+++ b/packages/react-reconciler/src/__tests__/DebugTracing-test.internal.js
@@ -67,7 +67,7 @@ describe('DebugTracing', () => {
         <React.unstable_DebugTracingMode>
           <div />
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
     expect(logs).toEqual([]);
@@ -179,7 +179,7 @@ describe('DebugTracing', () => {
             <Example />
           </React.Suspense>
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
 
@@ -216,7 +216,7 @@ describe('DebugTracing', () => {
             </React.Suspense>
           </Wrapper>
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
 
@@ -247,7 +247,7 @@ describe('DebugTracing', () => {
         <React.unstable_DebugTracingMode>
           <Example />
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
 
@@ -278,7 +278,7 @@ describe('DebugTracing', () => {
           <React.unstable_DebugTracingMode>
             <Example />
           </React.unstable_DebugTracingMode>,
-          {unstable_isConcurrent: true},
+          {isConcurrent: true},
         ),
       );
     }).toErrorDev('Cannot update during an existing state transition');
@@ -305,7 +305,7 @@ describe('DebugTracing', () => {
         <React.unstable_DebugTracingMode>
           <Example />
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
 
@@ -333,7 +333,7 @@ describe('DebugTracing', () => {
         <React.unstable_DebugTracingMode>
           <Example />
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
     expect(logs).toEqual([
@@ -358,7 +358,7 @@ describe('DebugTracing', () => {
         <React.unstable_DebugTracingMode>
           <Example />
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
 
@@ -381,7 +381,7 @@ describe('DebugTracing', () => {
         <React.unstable_DebugTracingMode>
           <Example />
         </React.unstable_DebugTracingMode>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       ),
     );
 
diff --git a/packages/react-reconciler/src/__tests__/ErrorBoundaryReconciliation-test.internal.js b/packages/react-reconciler/src/__tests__/ErrorBoundaryReconciliation-test.internal.js
index 71e047afc5ff6..0ce51699849b7 100644
--- a/packages/react-reconciler/src/__tests__/ErrorBoundaryReconciliation-test.internal.js
+++ b/packages/react-reconciler/src/__tests__/ErrorBoundaryReconciliation-test.internal.js
@@ -59,7 +59,7 @@ describe('ErrorBoundaryReconciliation', () => {
           <ErrorBoundary fallbackTagName={fallbackTagName}>
             <BrokenRender fail={false} />
           </ErrorBoundary>,
-          {unstable_isConcurrent: isConcurrent},
+          {isConcurrent: isConcurrent},
         );
       });
       expect(renderer).toMatchRenderedOutput(<span prop="BrokenRender" />);
diff --git a/packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js b/packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js
index 5f09cf997907c..5da503c8ca34d 100644
--- a/packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js
+++ b/packages/react-reconciler/src/__tests__/ReactHooks-test.internal.js
@@ -86,7 +86,7 @@ describe('ReactHooks', () => {
       return <Child text={text} />;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Parent />);
     await waitForAll(['Parent: 0, 0', 'Child: 0, 0', 'Effect: 0, 0']);
     expect(root).toMatchRenderedOutput('0, 0');
@@ -174,7 +174,7 @@ describe('ReactHooks', () => {
 
     Parent = memo(Parent);
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Parent theme="light" />);
     await waitForAll(['Parent: 0, 0 (light)', 'Child: 0, 0 (light)']);
     expect(root).toMatchRenderedOutput('0, 0 (light)');
@@ -232,7 +232,7 @@ describe('ReactHooks', () => {
       return counter;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Counter />);
     await waitForAll(['Count: 0']);
     expect(root).toMatchRenderedOutput('0');
@@ -266,7 +266,7 @@ describe('ReactHooks', () => {
       return counter;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Counter />);
     await waitForAll(['Count: 0']);
     expect(root).toMatchRenderedOutput('0');
@@ -322,7 +322,7 @@ describe('ReactHooks', () => {
       });
       return <Child text={text} />;
     }
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     await act(() => {
       root.update(
         <ThemeProvider>
@@ -390,7 +390,7 @@ describe('ReactHooks', () => {
       return <Child text={counter} />;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Parent />);
     await waitForAll(['Parent: 0', 'Child: 0', 'Effect: 0']);
     expect(root).toMatchRenderedOutput('0');
@@ -465,7 +465,7 @@ describe('ReactHooks', () => {
       return <Child text={counter} />;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Parent />);
     await waitForAll(['Parent: 0', 'Child: 0']);
     expect(root).toMatchRenderedOutput('0');
@@ -523,7 +523,7 @@ describe('ReactHooks', () => {
       return <Child text={counter} />;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
     root.update(<Parent />);
     await waitForAll(['Parent: 1', 'Child: 1']);
     expect(root).toMatchRenderedOutput('1');
diff --git a/packages/react-reconciler/src/__tests__/ReactLazy-test.internal.js b/packages/react-reconciler/src/__tests__/ReactLazy-test.internal.js
index a96c60bc26e88..36e956256dc60 100644
--- a/packages/react-reconciler/src/__tests__/ReactLazy-test.internal.js
+++ b/packages/react-reconciler/src/__tests__/ReactLazy-test.internal.js
@@ -99,7 +99,7 @@ describe('ReactLazy', () => {
         <LazyText text="Hi" />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -185,7 +185,7 @@ describe('ReactLazy', () => {
         <LazyBar />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -208,7 +208,7 @@ describe('ReactLazy', () => {
     const LazyText = lazy(async () => Text);
 
     const root = ReactTestRenderer.create(null, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     let error;
@@ -242,7 +242,7 @@ describe('ReactLazy', () => {
     });
 
     const root = ReactTestRenderer.create(null, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     let error;
@@ -302,7 +302,7 @@ describe('ReactLazy', () => {
     }
 
     const root = ReactTestRenderer.create(<Parent swap={false} />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Suspend! [LazyChildA]', 'Loading...']);
@@ -337,7 +337,7 @@ describe('ReactLazy', () => {
         <LazyText />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -394,7 +394,7 @@ describe('ReactLazy', () => {
         </Lazy>
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Loading...']);
@@ -440,7 +440,7 @@ describe('ReactLazy', () => {
         </Suspense>
       </>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Not lazy: 0', 'Loading...']);
@@ -485,7 +485,7 @@ describe('ReactLazy', () => {
         </Suspense>
       </>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Not lazy: 0', 'Loading...']);
@@ -561,7 +561,7 @@ describe('ReactLazy', () => {
         <LazyClass num={1} />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -691,7 +691,7 @@ describe('ReactLazy', () => {
         <LazyText />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -734,7 +734,7 @@ describe('ReactLazy', () => {
         <BadLazy />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -761,7 +761,7 @@ describe('ReactLazy', () => {
         <Lazy2 text="Hello" />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -815,7 +815,7 @@ describe('ReactLazy', () => {
         <LazyAdd inner="2" outer="2" />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -1012,7 +1012,7 @@ describe('ReactLazy', () => {
         <LazyText />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -1055,7 +1055,7 @@ describe('ReactLazy', () => {
         <LazyFoo />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -1100,7 +1100,7 @@ describe('ReactLazy', () => {
         <LazyForwardRef ref={ref} />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -1131,7 +1131,7 @@ describe('ReactLazy', () => {
         <LazyAdd outer={2} />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Loading...']);
@@ -1218,7 +1218,7 @@ describe('ReactLazy', () => {
         <LazyAdd outer={2} />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Loading...']);
@@ -1264,7 +1264,7 @@ describe('ReactLazy', () => {
         <LazyFoo ref={ref} />
       </Suspense>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -1304,7 +1304,7 @@ describe('ReactLazy', () => {
           <LazyText text="Hi" />
         </Suspense>
       </ErrorBoundary>,
-      {unstable_isConcurrent: true},
+      {isConcurrent: true},
     );
 
     await waitForAll(['Loading...']);
@@ -1412,7 +1412,7 @@ describe('ReactLazy', () => {
     }
 
     const root = ReactTestRenderer.create(<Parent swap={false} />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Init A', 'Loading...']);
@@ -1497,7 +1497,7 @@ describe('ReactLazy', () => {
     }
 
     const root = ReactTestRenderer.create(<Parent swap={false} />, {
-      unstable_isConcurrent: false,
+      isConcurrent: false,
     });
 
     assertLog(['Init A', 'Init B', 'Loading...']);
@@ -1559,7 +1559,7 @@ describe('ReactLazy', () => {
     }
 
     const root = ReactTestRenderer.create(<Parent swap={false} />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Init A', 'Loading...']);
@@ -1628,7 +1628,7 @@ describe('ReactLazy', () => {
     }
 
     const root = ReactTestRenderer.create(<Parent swap={false} />, {
-      unstable_isConcurrent: false,
+      isConcurrent: false,
     });
 
     assertLog(['Init A', 'Loading...']);
diff --git a/packages/react-reconciler/src/__tests__/ReactSuspense-test.internal.js b/packages/react-reconciler/src/__tests__/ReactSuspense-test.internal.js
index 6e347b900f655..4440f900294a7 100644
--- a/packages/react-reconciler/src/__tests__/ReactSuspense-test.internal.js
+++ b/packages/react-reconciler/src/__tests__/ReactSuspense-test.internal.js
@@ -117,7 +117,7 @@ describe('ReactSuspense', () => {
 
     // Render an empty shell
     const root = ReactTestRenderer.create(<Foo />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Foo']);
@@ -158,7 +158,7 @@ describe('ReactSuspense', () => {
         </Suspense>
       </>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
 
@@ -217,7 +217,7 @@ describe('ReactSuspense', () => {
         <Text text="Initial" />
       </>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Initial']);
@@ -268,7 +268,7 @@ describe('ReactSuspense', () => {
     }
 
     const root = ReactTestRenderer.create(<Foo />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Foo', 'Suspend! [A]', 'Loading...']);
@@ -303,7 +303,7 @@ describe('ReactSuspense', () => {
     }
 
     const root = ReactTestRenderer.create(<Foo />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Foo', 'Suspend! [A]', 'Loading...']);
@@ -353,7 +353,7 @@ describe('ReactSuspense', () => {
       }
 
       const root = ReactTestRenderer.create(null, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
 
       root.update(<App shouldSuspend={false} step={0} />);
@@ -456,7 +456,7 @@ describe('ReactSuspense', () => {
     }
 
     const root = ReactTestRenderer.create(<App />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
     await waitForAll(['Suspend! [default]', 'Loading...']);
 
@@ -502,7 +502,7 @@ describe('ReactSuspense', () => {
     }
 
     const root = ReactTestRenderer.create(<App />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
     await waitForAll(['Suspend! [default]', 'Loading...']);
 
@@ -545,7 +545,7 @@ describe('ReactSuspense', () => {
         </Suspense>
       </App>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Suspend! [default]', 'Loading...']);
@@ -589,7 +589,7 @@ describe('ReactSuspense', () => {
         </Suspense>
       </App>,
       {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       },
     );
     await waitForAll(['Suspend! [default]', 'Loading...']);
@@ -631,7 +631,7 @@ describe('ReactSuspense', () => {
     }
 
     const root = ReactTestRenderer.create(<App />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['Child 1', 'create layout']);
@@ -899,7 +899,7 @@ describe('ReactSuspense', () => {
       }
 
       const root = ReactTestRenderer.create(<App />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
 
       // Initial render
@@ -990,7 +990,7 @@ describe('ReactSuspense', () => {
       }
 
       const root = ReactTestRenderer.create(<App />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
 
       await waitForAll(['Suspend! [Child 1]', 'Loading...']);
diff --git a/packages/react-reconciler/src/__tests__/ReactSuspenseWithNoopRenderer-test.js b/packages/react-reconciler/src/__tests__/ReactSuspenseWithNoopRenderer-test.js
index d93c8bcf606ab..77aae6ee53d9b 100644
--- a/packages/react-reconciler/src/__tests__/ReactSuspenseWithNoopRenderer-test.js
+++ b/packages/react-reconciler/src/__tests__/ReactSuspenseWithNoopRenderer-test.js
@@ -5,6 +5,7 @@ let Scheduler;
 let act;
 let waitFor;
 let waitForAll;
+let waitForMicrotasks;
 let assertLog;
 let waitForPaint;
 let Suspense;
@@ -29,6 +30,7 @@ describe('ReactSuspenseWithNoopRenderer', () => {
     waitFor = InternalTestUtils.waitFor;
     waitForAll = InternalTestUtils.waitForAll;
     waitForPaint = InternalTestUtils.waitForPaint;
+    waitForMicrotasks = InternalTestUtils.waitForMicrotasks;
     assertLog = InternalTestUtils.assertLog;
 
     getCacheForType = React.unstable_getCacheForType;
@@ -4008,4 +4010,74 @@ describe('ReactSuspenseWithNoopRenderer', () => {
       );
     },
   );
+
+  // @gate enableLegacyCache && enableRetryLaneExpiration
+  it('recurring updates in siblings should not block expensive content in suspense boundary from committing', async () => {
+    const {useState} = React;
+
+    let setText;
+    function UpdatingText() {
+      const [text, _setText] = useState('1');
+      setText = _setText;
+      return <Text text={text} />;
+    }
+
+    function ExpensiveText({text, ms}) {
+      Scheduler.log(text);
+      Scheduler.unstable_advanceTime(ms);
+      return <span prop={text} />;
+    }
+
+    function App() {
+      return (
+        <>
+          <UpdatingText />
+          <Suspense fallback={<Text text="Loading..." />}>
+            <AsyncText text="Async" />
+            <ExpensiveText text="A" ms={1000} />
+            <ExpensiveText text="B" ms={3999} />
+            <ExpensiveText text="C" ms={100000} />
+          </Suspense>
+        </>
+      );
+    }
+
+    const root = ReactNoop.createRoot();
+    root.render(<App />);
+    await waitForAll(['1', 'Suspend! [Async]', 'Loading...']);
+    expect(root).toMatchRenderedOutput(
+      <>
+        <span prop="1" />
+        <span prop="Loading..." />
+      </>,
+    );
+
+    await resolveText('Async');
+    expect(root).toMatchRenderedOutput(
+      <>
+        <span prop="1" />
+        <span prop="Loading..." />
+      </>,
+    );
+
+    await waitFor(['Async', 'A', 'B']);
+    ReactNoop.expire(100000);
+    await advanceTimers(100000);
+    setText('2');
+    await waitForPaint(['2']);
+
+    await waitForMicrotasks();
+    Scheduler.unstable_flushNumberOfYields(1);
+    assertLog(['Async', 'A', 'B', 'C']);
+
+    expect(root).toMatchRenderedOutput(
+      <>
+        <span prop="2" />
+        <span prop="Async" />
+        <span prop="A" />
+        <span prop="B" />
+        <span prop="C" />
+      </>,
+    );
+  });
 });
diff --git a/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js b/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js
index f7c30616c98c1..af35defe2325c 100644
--- a/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js
+++ b/packages/react-reconciler/src/__tests__/StrictEffectsMode-test.js
@@ -76,7 +76,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -129,7 +129,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -182,7 +182,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -233,7 +233,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -286,7 +286,7 @@ describe('StrictEffectsMode', () => {
     }
 
     await act(() => {
-      ReactTestRenderer.create(<App />, {unstable_isConcurrent: true});
+      ReactTestRenderer.create(<App />, {isConcurrent: true});
     });
 
     if (supportsDoubleInvokeEffects()) {
@@ -322,7 +322,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -367,7 +367,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -438,7 +438,7 @@ describe('StrictEffectsMode', () => {
 
     await act(() => {
       ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -502,7 +502,7 @@ describe('StrictEffectsMode', () => {
     }
 
     await act(() => {
-      ReactTestRenderer.create(<App />, {unstable_isConcurrent: true});
+      ReactTestRenderer.create(<App />, {isConcurrent: true});
     });
 
     if (supportsDoubleInvokeEffects()) {
@@ -586,7 +586,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -667,7 +667,7 @@ describe('StrictEffectsMode', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<App text={'mount'} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
diff --git a/packages/react-refresh/src/__tests__/ReactFresh-test.js b/packages/react-refresh/src/__tests__/ReactFresh-test.js
index aa7b2504227e0..8ce009ed72043 100644
--- a/packages/react-refresh/src/__tests__/ReactFresh-test.js
+++ b/packages/react-refresh/src/__tests__/ReactFresh-test.js
@@ -34,7 +34,7 @@ describe('ReactFresh', () => {
       ReactDOM = require('react-dom');
       ReactDOMClient = require('react-dom/client');
       Scheduler = require('scheduler');
-      act = require('react-dom/test-utils').act;
+      act = React.unstable_act;
       internalAct = require('internal-test-utils').act;
 
       const InternalTestUtils = require('internal-test-utils');
@@ -3792,7 +3792,7 @@ describe('ReactFresh', () => {
       React = require('react');
       ReactDOM = require('react-dom');
       Scheduler = require('scheduler');
-      act = require('react-dom/test-utils').act;
+      act = React.unstable_act;
       internalAct = require('internal-test-utils').act;
 
       // Important! Inject into the global hook *after* ReactDOM runs:
diff --git a/packages/react-refresh/src/__tests__/ReactFreshIntegration-test.js b/packages/react-refresh/src/__tests__/ReactFreshIntegration-test.js
index 54e596f6232c3..ee7a9230bb14e 100644
--- a/packages/react-refresh/src/__tests__/ReactFreshIntegration-test.js
+++ b/packages/react-refresh/src/__tests__/ReactFreshIntegration-test.js
@@ -31,7 +31,7 @@ describe('ReactFreshIntegration', () => {
       ReactFreshRuntime = require('react-refresh/runtime');
       ReactFreshRuntime.injectIntoGlobalHook(global);
       ReactDOM = require('react-dom');
-      act = require('react-dom/test-utils').act;
+      act = React.unstable_act;
       container = document.createElement('div');
       document.body.appendChild(container);
       exportsObj = undefined;
diff --git a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOM-test.js b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOM-test.js
index eebca4710e954..c12c6904b872f 100644
--- a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOM-test.js
+++ b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOM-test.js
@@ -32,6 +32,7 @@ let ReactDOMClient;
 let ReactServerDOMServer;
 let ReactServerDOMClient;
 let ReactDOMFizzServer;
+let ReactDOMStaticServer;
 let Suspense;
 let ErrorBoundary;
 let JSDOM;
@@ -71,6 +72,7 @@ describe('ReactFlightDOM', () => {
     Suspense = React.Suspense;
     ReactDOMClient = require('react-dom/client');
     ReactDOMFizzServer = require('react-dom/server.node');
+    ReactDOMStaticServer = require('react-dom/static.node');
     ReactServerDOMClient = require('react-server-dom-webpack/client');
 
     ErrorBoundary = class extends React.Component {
@@ -1300,6 +1302,91 @@ describe('ReactFlightDOM', () => {
     expect(getMeaningfulChildren(container)).toEqual(<p>hello world</p>);
   });
 
+  // @gate enablePostpone
+  it('should allow postponing in Flight through a serialized promise', async () => {
+    const Context = React.createContext();
+    const ContextProvider = Context.Provider;
+
+    function Foo() {
+      const value = React.use(React.useContext(Context));
+      return <span>{value}</span>;
+    }
+
+    const ClientModule = clientExports({
+      ContextProvider,
+      Foo,
+    });
+
+    async function getFoo() {
+      React.unstable_postpone('foo');
+    }
+
+    function App() {
+      return (
+        <ClientModule.ContextProvider value={getFoo()}>
+          <div>
+            <Suspense fallback="loading...">
+              <ClientModule.Foo />
+            </Suspense>
+          </div>
+        </ClientModule.ContextProvider>
+      );
+    }
+
+    const {writable, readable} = getTestStream();
+
+    const {pipe} = ReactServerDOMServer.renderToPipeableStream(
+      <App />,
+      webpackMap,
+    );
+    pipe(writable);
+
+    let response = null;
+    function getResponse() {
+      if (response === null) {
+        response = ReactServerDOMClient.createFromReadableStream(readable);
+      }
+      return response;
+    }
+
+    function Response() {
+      return getResponse();
+    }
+
+    const errors = [];
+    function onError(error, errorInfo) {
+      errors.push(error, errorInfo);
+    }
+    const result = await ReactDOMStaticServer.prerenderToNodeStream(
+      <Response />,
+      {
+        onError,
+      },
+    );
+
+    const prelude = await new Promise((resolve, reject) => {
+      let content = '';
+      result.prelude.on('data', chunk => {
+        content += Buffer.from(chunk).toString('utf8');
+      });
+      result.prelude.on('error', error => {
+        reject(error);
+      });
+      result.prelude.on('end', () => resolve(content));
+    });
+
+    expect(errors).toEqual([]);
+    const doc = new JSDOM(prelude).window.document;
+    expect(getMeaningfulChildren(doc)).toEqual(
+      <html>
+        <head />
+        <body>
+          <div>loading...</div>
+        </body>
+      </html>,
+    );
+  });
+
   it('should support float methods when rendering in Fizz', async () => {
     function Component() {
       return <p>hello world</p>;
diff --git a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMForm-test.js b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMForm-test.js
index d21c456b8e087..89b436907f201 100644
--- a/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMForm-test.js
+++ b/packages/react-server-dom-webpack/src/__tests__/ReactFlightDOMForm-test.js
@@ -54,7 +54,7 @@ describe('ReactFlightDOMForm', () => {
     ReactServerDOMClient = require('react-server-dom-webpack/client.edge');
     ReactDOMServer = require('react-dom/server.edge');
     ReactDOMClient = require('react-dom/client');
-    act = require('react-dom/test-utils').act;
+    act = React.unstable_act;
     useFormState = require('react-dom').useFormState;
     container = document.createElement('div');
     document.body.appendChild(container);
diff --git a/packages/react-server/src/ReactFlightServer.js b/packages/react-server/src/ReactFlightServer.js
index 479a4a746d5e2..cc65f746f42e8 100644
--- a/packages/react-server/src/ReactFlightServer.js
+++ b/packages/react-server/src/ReactFlightServer.js
@@ -407,11 +407,21 @@ function serializeThenable(request: Request, thenable: Thenable<any>): number {
       pingTask(request, newTask);
     },
     reason => {
-      newTask.status = ERRORED;
+      if (
+        enablePostpone &&
+        typeof reason === 'object' &&
+        reason !== null &&
+        (reason: any).$$typeof === REACT_POSTPONE_TYPE
+      ) {
+        const postponeInstance: Postpone = (reason: any);
+        logPostpone(request, postponeInstance.message);
+        emitPostponeChunk(request, newTask.id, postponeInstance);
+      } else {
+        newTask.status = ERRORED;
+        const digest = logRecoverableError(request, reason);
+        emitErrorChunk(request, newTask.id, digest, reason);
+      }
       request.abortableTasks.delete(newTask);
-      // TODO: We should ideally do this inside performWork so it's scheduled
-      const digest = logRecoverableError(request, reason);
-      emitErrorChunk(request, newTask.id, digest, reason);
       if (request.destination !== null) {
         flushCompletedChunks(request, request.destination);
       }
diff --git a/packages/react-test-renderer/src/ReactTestRenderer.js b/packages/react-test-renderer/src/ReactTestRenderer.js
index 273bcd128f47c..4b19f599db5ac 100644
--- a/packages/react-test-renderer/src/ReactTestRenderer.js
+++ b/packages/react-test-renderer/src/ReactTestRenderer.js
@@ -60,6 +60,7 @@ const act = React.unstable_act;
 
 type TestRendererOptions = {
   createNodeMock: (element: React$Element<any>) => any,
+  isConcurrent: boolean,
   unstable_isConcurrent: boolean,
   unstable_strictMode: boolean,
   unstable_concurrentUpdatesByDefault: boolean,
@@ -479,7 +480,10 @@ function create(
       // $FlowFixMe[incompatible-type] found when upgrading Flow
       createNodeMock = options.createNodeMock;
     }
-    if (options.unstable_isConcurrent === true) {
+    if (
+      options.unstable_isConcurrent === true ||
+      options.isConcurrent === true
+    ) {
       isConcurrent = true;
     }
     if (options.unstable_strictMode === true) {
diff --git a/packages/react-test-renderer/src/__tests__/ReactTestRendererAsync-test.js b/packages/react-test-renderer/src/__tests__/ReactTestRendererAsync-test.js
index 468f62d39a722..51c7e0a950ddc 100644
--- a/packages/react-test-renderer/src/__tests__/ReactTestRendererAsync-test.js
+++ b/packages/react-test-renderer/src/__tests__/ReactTestRendererAsync-test.js
@@ -34,7 +34,7 @@ describe('ReactTestRendererAsync', () => {
       return props.children;
     }
     const renderer = ReactTestRenderer.create(<Foo>Hi</Foo>, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     // Before flushing, nothing has mounted.
@@ -68,7 +68,7 @@ describe('ReactTestRendererAsync', () => {
       );
     }
     const renderer = ReactTestRenderer.create(<Parent step={1} />, {
-      unstable_isConcurrent: true,
+      isConcurrent: true,
     });
 
     await waitForAll(['A:1', 'B:1', 'C:1']);
@@ -97,7 +97,7 @@ describe('ReactTestRendererAsync', () => {
     let renderer;
     React.startTransition(() => {
       renderer = ReactTestRenderer.create(<Parent step={1} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
@@ -137,7 +137,7 @@ describe('ReactTestRendererAsync', () => {
     let renderer;
     React.startTransition(() => {
       renderer = ReactTestRenderer.create(<Example step={1} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
diff --git a/packages/react/src/__tests__/ReactProfiler-test.internal.js b/packages/react/src/__tests__/ReactProfiler-test.internal.js
index 25386df33abcf..fd42561393101 100644
--- a/packages/react/src/__tests__/ReactProfiler-test.internal.js
+++ b/packages/react/src/__tests__/ReactProfiler-test.internal.js
@@ -213,7 +213,7 @@ describe(`onRender`, () => {
           <Yield value="last" />
         </React.Profiler>,
         {
-          unstable_isConcurrent: true,
+          isConcurrent: true,
         },
       );
     });
@@ -752,7 +752,7 @@ describe(`onRender`, () => {
             <Yield renderTime={2} />
             <Yield renderTime={3} />
           </React.Profiler>,
-          {unstable_isConcurrent: true},
+          {isConcurrent: true},
         );
       });
 
@@ -793,7 +793,7 @@ describe(`onRender`, () => {
               <Yield renderTime={17} />
             </React.Profiler>
           </React.Profiler>,
-          {unstable_isConcurrent: true},
+          {isConcurrent: true},
         );
       });
 
@@ -844,7 +844,7 @@ describe(`onRender`, () => {
             <Yield renderTime={10} />
             <Yield renderTime={20} />
           </React.Profiler>,
-          {unstable_isConcurrent: true},
+          {isConcurrent: true},
         );
       });
 
@@ -897,7 +897,7 @@ describe(`onRender`, () => {
           <Yield renderTime={6} />
           <Yield renderTime={15} />
         </React.Profiler>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
 
       // Render everything initially.
@@ -1002,7 +1002,7 @@ describe(`onRender`, () => {
           <FirstComponent />
           <SecondComponent />
         </React.Profiler>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
 
       // Render everything initially.
diff --git a/packages/react/src/__tests__/ReactProfilerDevToolsIntegration-test.internal.js b/packages/react/src/__tests__/ReactProfilerDevToolsIntegration-test.internal.js
index d28e2ad8de64a..572abd354da63 100644
--- a/packages/react/src/__tests__/ReactProfilerDevToolsIntegration-test.internal.js
+++ b/packages/react/src/__tests__/ReactProfilerDevToolsIntegration-test.internal.js
@@ -150,7 +150,7 @@ describe('ReactProfiler DevTools integration', () => {
       return text;
     }
 
-    const root = ReactTestRenderer.create(null, {unstable_isConcurrent: true});
+    const root = ReactTestRenderer.create(null, {isConcurrent: true});
 
     // Commit something
     root.update(<Text text="A" />);
diff --git a/packages/react/src/__tests__/ReactStartTransition-test.js b/packages/react/src/__tests__/ReactStartTransition-test.js
index 9e689ac6e7105..c98372a7c74b7 100644
--- a/packages/react/src/__tests__/ReactStartTransition-test.js
+++ b/packages/react/src/__tests__/ReactStartTransition-test.js
@@ -49,7 +49,7 @@ describe('ReactStartTransition', () => {
 
     await act(() => {
       ReactTestRenderer.create(<Component level={0} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
 
diff --git a/packages/scheduler/src/SchedulerFeatureFlags.js b/packages/scheduler/src/SchedulerFeatureFlags.js
index 182093a93c85c..5d207922ca968 100644
--- a/packages/scheduler/src/SchedulerFeatureFlags.js
+++ b/packages/scheduler/src/SchedulerFeatureFlags.js
@@ -14,3 +14,7 @@ export const enableIsInputPendingContinuous = false;
 export const frameYieldMs = 5;
 export const continuousYieldMs = 50;
 export const maxYieldMs = 300;
+
+export const userBlockingPriorityTimeout = 250;
+export const normalPriorityTimeout = 5000;
+export const lowPriorityTimeout = 10000;
diff --git a/packages/scheduler/src/forks/Scheduler.js b/packages/scheduler/src/forks/Scheduler.js
index 2263b706aad35..e4eb17b37a2c9 100644
--- a/packages/scheduler/src/forks/Scheduler.js
+++ b/packages/scheduler/src/forks/Scheduler.js
@@ -19,6 +19,9 @@ import {
   frameYieldMs,
   continuousYieldMs,
   maxYieldMs,
+  userBlockingPriorityTimeout,
+  lowPriorityTimeout,
+  normalPriorityTimeout,
 } from '../SchedulerFeatureFlags';
 
 import {push, pop, peek} from '../SchedulerMinHeap';
@@ -75,15 +78,6 @@ if (hasPerformanceNow) {
 // 0b111111111111111111111111111111
 var maxSigned31BitInt = 1073741823;
 
-// Times out immediately
-var IMMEDIATE_PRIORITY_TIMEOUT = -1;
-// Eventually times out
-var USER_BLOCKING_PRIORITY_TIMEOUT = 250;
-var NORMAL_PRIORITY_TIMEOUT = 5000;
-var LOW_PRIORITY_TIMEOUT = 10000;
-// Never times out
-var IDLE_PRIORITY_TIMEOUT = maxSigned31BitInt;
-
 // Tasks are stored on a min heap
 var taskQueue: Array<Task> = [];
 var timerQueue: Array<Task> = [];
@@ -362,20 +356,25 @@ function unstable_scheduleCallback(
   var timeout;
   switch (priorityLevel) {
     case ImmediatePriority:
-      timeout = IMMEDIATE_PRIORITY_TIMEOUT;
+      // Times out immediately
+      timeout = -1;
       break;
     case UserBlockingPriority:
-      timeout = USER_BLOCKING_PRIORITY_TIMEOUT;
+      // Eventually times out
+      timeout = userBlockingPriorityTimeout;
       break;
     case IdlePriority:
-      timeout = IDLE_PRIORITY_TIMEOUT;
+      // Never times out
+      timeout = maxSigned31BitInt;
       break;
     case LowPriority:
-      timeout = LOW_PRIORITY_TIMEOUT;
+      // Eventually times out
+      timeout = lowPriorityTimeout;
       break;
     case NormalPriority:
     default:
-      timeout = NORMAL_PRIORITY_TIMEOUT;
+      // Eventually times out
+      timeout = normalPriorityTimeout;
       break;
   }
 
diff --git a/packages/scheduler/src/forks/SchedulerFeatureFlags.www-dynamic.js b/packages/scheduler/src/forks/SchedulerFeatureFlags.www-dynamic.js
index 8232400b84d32..25d88aa4b903d 100644
--- a/packages/scheduler/src/forks/SchedulerFeatureFlags.www-dynamic.js
+++ b/packages/scheduler/src/forks/SchedulerFeatureFlags.www-dynamic.js
@@ -12,3 +12,7 @@
 // with the __VARIANT__ set to `true`, and once set to `false`.
 
 export const enableProfiling = __VARIANT__;
+
+export const userBlockingPriorityTimeout = 250;
+export const normalPriorityTimeout = 5000;
+export const lowPriorityTimeout = 10000;
diff --git a/packages/scheduler/src/forks/SchedulerFeatureFlags.www.js b/packages/scheduler/src/forks/SchedulerFeatureFlags.www.js
index 4ad93cb70e594..a0713261db996 100644
--- a/packages/scheduler/src/forks/SchedulerFeatureFlags.www.js
+++ b/packages/scheduler/src/forks/SchedulerFeatureFlags.www.js
@@ -7,10 +7,16 @@
  * @flow
  */
 
-const {enableProfiling: enableProfilingFeatureFlag} =
-  // $FlowFixMe[cannot-resolve-module]
-  require('SchedulerFeatureFlags');
+// $FlowFixMe[cannot-resolve-module]
+const dynamicFeatureFlags = require('SchedulerFeatureFlags');
 
+const {enableProfiling: enableProfilingFeatureFlag} = dynamicFeatureFlags;
+
+export const {
+  userBlockingPriorityTimeout,
+  normalPriorityTimeout,
+  lowPriorityTimeout,
+} = dynamicFeatureFlags;
 export const enableSchedulerDebugging = true;
 export const enableProfiling: boolean =
   __PROFILE__ && enableProfilingFeatureFlag;
diff --git a/packages/shared/ReactFeatureFlags.js b/packages/shared/ReactFeatureFlags.js
index 2ede92b1c06e0..acf2e6e9b9dcc 100644
--- a/packages/shared/ReactFeatureFlags.js
+++ b/packages/shared/ReactFeatureFlags.js
@@ -130,6 +130,9 @@ export const enableUseDeferredValueInitialArg = __EXPERIMENTAL__;
  * Enables an expiration time for retry lanes to avoid starvation.
  */
 export const enableRetryLaneExpiration = false;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 // -----------------------------------------------------------------------------
 // Chopping Block
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js b/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js
index 4d488410a55db..91a518a905154 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb-dynamic.js
@@ -21,7 +21,6 @@ import typeof * as DynamicFlagsType from 'ReactNativeInternalFeatureFlags';
 // update the test configuration.
 
 export const alwaysThrottleRetries = __VARIANT__;
-export const disableModulePatternComponents = __VARIANT__;
 export const enableDeferRootSchedulingToMicrotask = __VARIANT__;
 export const enableUnifiedSyncLane = __VARIANT__;
 export const enableUseRefAccessWarning = __VARIANT__;
diff --git a/packages/shared/forks/ReactFeatureFlags.native-fb.js b/packages/shared/forks/ReactFeatureFlags.native-fb.js
index 3d228b88440be..8c8ff2cbf97bb 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-fb.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-fb.js
@@ -19,7 +19,6 @@ import * as dynamicFlags from 'ReactNativeInternalFeatureFlags';
 // the exports object every time a flag is read.
 export const {
   alwaysThrottleRetries,
-  disableModulePatternComponents,
   enableDeferRootSchedulingToMicrotask,
   enableUnifiedSyncLane,
   enableUseRefAccessWarning,
@@ -28,6 +27,7 @@ export const {
 } = dynamicFlags;
 
 // The rest of the flags are static for better dead code elimination.
+export const disableModulePatternComponents = true;
 export const enableDebugTracing = false;
 export const enableSchedulingProfiler = __PROFILE__;
 export const enableProfilerTimer = __PROFILE__;
@@ -66,7 +66,11 @@ export const enableComponentStackLocations = false;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const enableGetInspectorDataForInstanceInProduction = true;
+
 export const enableRetryLaneExpiration = false;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 export const createRootStrictEffectsByDefault = false;
 
diff --git a/packages/shared/forks/ReactFeatureFlags.native-oss.js b/packages/shared/forks/ReactFeatureFlags.native-oss.js
index b8203b3b3cbcb..795fab334ee80 100644
--- a/packages/shared/forks/ReactFeatureFlags.native-oss.js
+++ b/packages/shared/forks/ReactFeatureFlags.native-oss.js
@@ -49,7 +49,11 @@ export const enableComponentStackLocations = false;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const enableGetInspectorDataForInstanceInProduction = false;
+
 export const enableRetryLaneExpiration = false;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
index 611160e2a1f6a..e0216e3f57535 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.js
@@ -49,7 +49,11 @@ export const enableComponentStackLocations = true;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = false;
 export const enableGetInspectorDataForInstanceInProduction = false;
+
 export const enableRetryLaneExpiration = false;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
index 60a15318c7c00..93d09f741601e 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.native.js
@@ -51,7 +51,11 @@ export const enableUseEffectEventHook = false;
 export const enableClientRenderFallbackOnTextMismatch = true;
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
+
 export const enableRetryLaneExpiration = false;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 export const disableSchedulerTimeoutInWorkLoop = false;
 export const enableLazyContextPropagation = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
index c5678792313ae..d5fa0454eaaf0 100644
--- a/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.test-renderer.www.js
@@ -49,7 +49,11 @@ export const enableComponentStackLocations = true;
 export const enableLegacyFBSupport = false;
 export const enableFilterEmptyStringAttributesDOM = true;
 export const enableGetInspectorDataForInstanceInProduction = false;
+
 export const enableRetryLaneExpiration = false;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 export const createRootStrictEffectsByDefault = false;
 export const enableUseRefAccessWarning = false;
diff --git a/packages/shared/forks/ReactFeatureFlags.www-dynamic.js b/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
index b824c9ac8323c..74c0ab2f6f5fd 100644
--- a/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
+++ b/packages/shared/forks/ReactFeatureFlags.www-dynamic.js
@@ -29,7 +29,11 @@ export const enableAsyncActions = __VARIANT__;
 export const alwaysThrottleRetries = __VARIANT__;
 export const enableDO_NOT_USE_disableStrictPassiveEffect = __VARIANT__;
 export const enableUseDeferredValueInitialArg = __VARIANT__;
+
 export const enableRetryLaneExpiration = __VARIANT__;
+export const retryLaneExpirationMs = 5000;
+export const syncLaneExpirationMs = 250;
+export const transitionLaneExpirationMs = 5000;
 
 // Enable this flag to help with concurrent mode debugging.
 // It logs information to the console about React scheduling, rendering, and commit phases.
diff --git a/packages/shared/forks/ReactFeatureFlags.www.js b/packages/shared/forks/ReactFeatureFlags.www.js
index 9f7724d0771c0..a76277e43b864 100644
--- a/packages/shared/forks/ReactFeatureFlags.www.js
+++ b/packages/shared/forks/ReactFeatureFlags.www.js
@@ -33,6 +33,9 @@ export const {
   enableDO_NOT_USE_disableStrictPassiveEffect,
   disableSchedulerTimeoutInWorkLoop,
   enableUseDeferredValueInitialArg,
+  retryLaneExpirationMs,
+  syncLaneExpirationMs,
+  transitionLaneExpirationMs,
 } = dynamicFeatureFlags;
 
 // On WWW, __EXPERIMENTAL__ is used for a new modern build.
diff --git a/packages/use-subscription/src/__tests__/useSubscription-test.js b/packages/use-subscription/src/__tests__/useSubscription-test.js
index 19eba0a15be8e..9c971bd14bbb3 100644
--- a/packages/use-subscription/src/__tests__/useSubscription-test.js
+++ b/packages/use-subscription/src/__tests__/useSubscription-test.js
@@ -84,7 +84,7 @@ describe('useSubscription', () => {
     await act(() => {
       renderer = ReactTestRenderer.create(
         <Subscription source={observable} />,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
     assertLog(['default']);
@@ -136,7 +136,7 @@ describe('useSubscription', () => {
     await act(() => {
       renderer = ReactTestRenderer.create(
         <Subscription source={observable} />,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
     assertLog(['initial']);
@@ -185,7 +185,7 @@ describe('useSubscription', () => {
     await act(() => {
       renderer = ReactTestRenderer.create(
         <Subscription source={observableA} />,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
 
@@ -244,7 +244,7 @@ describe('useSubscription', () => {
     await act(() => {
       renderer = ReactTestRenderer.create(
         <Subscription source={observableA} />,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
 
@@ -331,7 +331,7 @@ describe('useSubscription', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<Parent observed={observableA} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
     assertLog(['Child: a-0', 'Grandchild: a-0']);
@@ -434,7 +434,7 @@ describe('useSubscription', () => {
     let renderer;
     await act(() => {
       renderer = ReactTestRenderer.create(<Parent observed={observableA} />, {
-        unstable_isConcurrent: true,
+        isConcurrent: true,
       });
     });
     assertLog(['Child: a-0', 'Grandchild: a-0']);
@@ -532,7 +532,7 @@ describe('useSubscription', () => {
     await act(() => {
       renderer = ReactTestRenderer.create(
         <Subscription source={eventHandler} />,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
     assertLog([true]);
@@ -566,7 +566,7 @@ describe('useSubscription', () => {
     await act(() => {
       renderer = ReactTestRenderer.create(
         <Subscription subscription={subscription1} />,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
     });
     await waitForAll([]);
@@ -607,7 +607,7 @@ describe('useSubscription', () => {
           <Subscriber id="first" />
           <Subscriber id="second" />
         </React.Fragment>,
-        {unstable_isConcurrent: true},
+        {isConcurrent: true},
       );
       await waitForAll(['render:first:A', 'render:second:A']);
 
diff --git a/scripts/flow/xplat.js b/scripts/flow/xplat.js
index fadbe3161aa26..b2c4709a3b566 100644
--- a/scripts/flow/xplat.js
+++ b/scripts/flow/xplat.js
@@ -9,7 +9,6 @@
 
 declare module 'ReactNativeInternalFeatureFlags' {
   declare export var alwaysThrottleRetries: boolean;
-  declare export var disableModulePatternComponents: boolean;
   declare export var enableDeferRootSchedulingToMicrotask: boolean;
   declare export var enableUnifiedSyncLane: boolean;
   declare export var enableUseRefAccessWarning: boolean;
diff --git a/scripts/print-warnings/print-warnings.js b/scripts/print-warnings/print-warnings.js
index 95cc882cb7724..69b986b3a0d58 100644
--- a/scripts/print-warnings/print-warnings.js
+++ b/scripts/print-warnings/print-warnings.js
@@ -75,19 +75,23 @@ gs([
   '!**/node_modules/**/*.js',
 ]).pipe(
   through.obj(transform, cb => {
-    if (process.argv[2] === '--js') {
-      const warningsArray = Array.from(warnings);
-      warningsArray.sort();
-      process.stdout.write(
-        `export default ${JSON.stringify(warningsArray, null, 2)};\n`
-      );
-    } else {
-      process.stdout.write(
-        Array.from(warnings, warning => JSON.stringify(warning))
-          .sort()
-          .join('\n') + '\n'
-      );
-    }
+    const warningsArray = Array.from(warnings);
+    warningsArray.sort();
+    process.stdout.write(
+      `/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @noformat
+ * @oncall react_core
+ */
+
+export default ${JSON.stringify(warningsArray, null, 2)};
+`
+    );
     cb();
   })
 );