This is an initial stab at replicating the demo app for Turbo iOS, but using SwiftUI.
I think that if I understood Swift's type system better, TurboNavigationHelper#stack could be replaced with an object that is like NavigationPath. What this would hopefully mean is that you could have a type-erased array of Hashable object that you could still have the functionality of appendOrPopTo, but then you wouldn't need NavigationDatum. Instead, you could have as bunch of navigationDestination calls for the different specific types of data that could be in that array.