diff --git a/mm2src/coins/eth/fee_estimation/eth_fee_events.rs b/mm2src/coins/eth/fee_estimation/eth_fee_events.rs
index 852988ef9e..8d91790374 100644
--- a/mm2src/coins/eth/fee_estimation/eth_fee_events.rs
+++ b/mm2src/coins/eth/fee_estimation/eth_fee_events.rs
@@ -43,6 +43,7 @@ pub struct EthFeeEventStreamer {
 }
 
 impl EthFeeEventStreamer {
+    #[inline(always)]
     pub fn new(config: EthFeeStreamingConfig, coin: EthCoin) -> Self { Self { config, coin } }
 }
 
diff --git a/mm2src/coins/eth/fee_estimation/rpc.rs b/mm2src/coins/eth/fee_estimation/rpc.rs
index 111d8c7979..6fb3b84498 100644
--- a/mm2src/coins/eth/fee_estimation/rpc.rs
+++ b/mm2src/coins/eth/fee_estimation/rpc.rs
@@ -3,7 +3,7 @@ use super::ser::FeePerGasEstimated;
 use crate::{lp_coinfind, MmCoinEnum};
 use common::HttpStatusCode;
 use mm2_core::mm_ctx::MmArc;
-use mm2_err_handle::mm_error::MmResult;
+use mm2_err_handle::mm_error::{MmError, MmResult};
 
 use http::StatusCode;
 use std::convert::TryFrom;
@@ -36,13 +36,8 @@ pub async fn get_eth_estimated_fee_per_gas(
     ctx: MmArc,
     req: GetFeeEstimationRequest,
 ) -> MmResult<FeePerGasEstimated, GetFeeEstimationRequestError> {
-    let coin = lp_coinfind(&ctx, &req.coin)
-        .await
-        .map_err(GetFeeEstimationRequestError::Internal)?
-        .ok_or(GetFeeEstimationRequestError::CoinNotFound)?;
-
-    match coin {
-        MmCoinEnum::EthCoin(coin) => {
+    match lp_coinfind(&ctx, &req.coin).await {
+        Ok(Some(MmCoinEnum::EthCoin(coin))) => {
             let use_simple = matches!(req.estimator_type, EstimatorType::Simple);
             let fee = coin
                 .get_eip1559_gas_fee(use_simple)
@@ -52,6 +47,8 @@ pub async fn get_eth_estimated_fee_per_gas(
                 FeePerGasEstimated::try_from(fee).map_err(|e| GetFeeEstimationRequestError::Internal(e.to_string()))?;
             Ok(ser_fee)
         },
-        _ => Err(GetFeeEstimationRequestError::CoinNotSupported)?,
+        Ok(Some(_)) => MmError::err(GetFeeEstimationRequestError::CoinNotSupported),
+        Ok(None) => MmError::err(GetFeeEstimationRequestError::CoinNotFound),
+        Err(e) => MmError::err(GetFeeEstimationRequestError::Internal(e)),
     }
 }
diff --git a/mm2src/coins/tendermint/tendermint_tx_history_v2.rs b/mm2src/coins/tendermint/tendermint_tx_history_v2.rs
index ece9b6a89c..9e83f707cc 100644
--- a/mm2src/coins/tendermint/tendermint_tx_history_v2.rs
+++ b/mm2src/coins/tendermint/tendermint_tx_history_v2.rs
@@ -588,6 +588,7 @@ where
                 "could not get rpc client"
             );
 
+            let streaming_manager = coin.get_ctx().unwrap().event_stream_manager.clone();
             loop {
                 let response = try_or_return_stopped_as_err!(
                     client
@@ -755,9 +756,7 @@ where
                     log::debug!("Tx '{}' successfully parsed.", tx.hash);
                 }
 
-                coin.get_ctx()
-                    .unwrap()
-                    .event_stream_manager
+                streaming_manager
                     .send_fn(&TxHistoryEventStreamer::derive_streamer_id(coin.ticker()), || {
                         tx_details.clone()
                     })
diff --git a/mm2src/coins/utxo/tx_history_events.rs b/mm2src/coins/utxo/tx_history_events.rs
index 902fb5baeb..c336e6fbb0 100644
--- a/mm2src/coins/utxo/tx_history_events.rs
+++ b/mm2src/coins/utxo/tx_history_events.rs
@@ -10,8 +10,10 @@ pub struct TxHistoryEventStreamer {
 }
 
 impl TxHistoryEventStreamer {
+    #[inline(always)]
     pub fn new(coin: String) -> Self { Self { coin } }
 
+    #[inline(always)]
     pub fn derive_streamer_id(coin: &str) -> String { format!("TX_HISTORY:{coin}") }
 }
 
diff --git a/mm2src/coins/utxo/utxo_tx_history_v2.rs b/mm2src/coins/utxo/utxo_tx_history_v2.rs
index 8670ceaac8..c60588e226 100644
--- a/mm2src/coins/utxo/utxo_tx_history_v2.rs
+++ b/mm2src/coins/utxo/utxo_tx_history_v2.rs
@@ -590,6 +590,7 @@ where
 
         let my_addresses = try_or_stop_unknown!(ctx.coin.my_addresses().await, "Error on getting my addresses");
 
+        let streaming_manager = ctx.coin.get_ctx().unwrap().event_stream_manager.clone();
         for (tx_hash, height) in self.all_tx_ids_with_height {
             let tx_hash_string = format!("{:02x}", tx_hash);
             match ctx.storage.history_has_tx_hash(&wallet_id, &tx_hash_string).await {
@@ -621,10 +622,7 @@ where
                 },
             };
 
-            ctx.coin
-                .get_ctx()
-                .unwrap()
-                .event_stream_manager
+            streaming_manager
                 .send_fn(&TxHistoryEventStreamer::derive_streamer_id(ctx.coin.ticker()), || {
                     tx_details.clone()
                 })
diff --git a/mm2src/coins/z_coin/tx_history_events.rs b/mm2src/coins/z_coin/tx_history_events.rs
index 9097d581c7..beb57a2b1a 100644
--- a/mm2src/coins/z_coin/tx_history_events.rs
+++ b/mm2src/coins/z_coin/tx_history_events.rs
@@ -19,8 +19,10 @@ pub struct ZCoinTxHistoryEventStreamer {
 }
 
 impl ZCoinTxHistoryEventStreamer {
+    #[inline(always)]
     pub fn new(coin: ZCoin) -> Self { Self { coin } }
 
+    #[inline(always)]
     pub fn derive_streamer_id(coin: &str) -> String { format!("TX_HISTORY:{coin}") }
 }
 
diff --git a/mm2src/coins/z_coin/z_balance_streaming.rs b/mm2src/coins/z_coin/z_balance_streaming.rs
index 2b29f093ed..18b2c6ef38 100644
--- a/mm2src/coins/z_coin/z_balance_streaming.rs
+++ b/mm2src/coins/z_coin/z_balance_streaming.rs
@@ -19,8 +19,10 @@ pub struct ZCoinBalanceEventStreamer {
 }
 
 impl ZCoinBalanceEventStreamer {
+    #[inline(always)]
     pub fn new(coin: ZCoin) -> Self { Self { coin } }
 
+    #[inline(always)]
     pub fn derive_streamer_id(coin: &str) -> String { format!("BALANCE:{coin}") }
 }
 
diff --git a/mm2src/mm2_event_stream/src/event.rs b/mm2src/mm2_event_stream/src/event.rs
index 93b1918d6a..57931b9817 100644
--- a/mm2src/mm2_event_stream/src/event.rs
+++ b/mm2src/mm2_event_stream/src/event.rs
@@ -2,9 +2,9 @@ use serde_json::Value as Json;
 
 // Note `Event` shouldn't be `Clone`able, but rather Arc/Rc wrapped and then shared.
 // This is only for testing.
+/// Multi-purpose/generic event type that can easily be used over the event streaming
 #[cfg_attr(test, derive(Clone, Debug, PartialEq))]
 #[derive(Default)]
-/// Multi-purpose/generic event type that can easily be used over the event streaming
 pub struct Event {
     /// The type of the event (balance, network, swap, etc...).
     event_type: String,
@@ -16,7 +16,7 @@ pub struct Event {
 
 impl Event {
     /// Creates a new `Event` instance with the specified event type and message.
-    #[inline]
+    #[inline(always)]
     pub fn new(streamer_id: String, message: Json) -> Self {
         Self {
             event_type: streamer_id,
@@ -26,7 +26,7 @@ impl Event {
     }
 
     /// Create a new error `Event` instance with the specified error event type and message.
-    #[inline]
+    #[inline(always)]
     pub fn err(streamer_id: String, message: Json) -> Self {
         Self {
             event_type: streamer_id,
@@ -36,8 +36,10 @@ impl Event {
     }
 
     /// Returns the `event_type` (the ID of the streamer firing this event).
+    #[inline(always)]
     pub fn origin(&self) -> &str { &self.event_type }
 
+    /// Returns the event type and message as a pair.
     pub fn get(&self) -> (String, Json) {
         let prefix = if self.error { "ERROR:" } else { "" };
         (format!("{prefix}{}", self.event_type), self.message.clone())
diff --git a/mm2src/mm2_main/src/lp_ordermatch/order_events.rs b/mm2src/mm2_main/src/lp_ordermatch/order_events.rs
index 0ba4dc3905..547ee7df4e 100644
--- a/mm2src/mm2_main/src/lp_ordermatch/order_events.rs
+++ b/mm2src/mm2_main/src/lp_ordermatch/order_events.rs
@@ -8,9 +8,11 @@ use futures::StreamExt;
 pub struct OrderStatusStreamer;
 
 impl OrderStatusStreamer {
+    #[inline(always)]
     pub fn new() -> Self { Self }
 
-    pub fn derive_streamer_id() -> &'static str { "ORDER_STATUS" }
+    #[inline(always)]
+    pub const fn derive_streamer_id() -> &'static str { "ORDER_STATUS" }
 }
 
 #[derive(Serialize)]
diff --git a/mm2src/mm2_main/src/lp_swap/swap_events.rs b/mm2src/mm2_main/src/lp_swap/swap_events.rs
index a7dcfef3b8..7f4aaa90eb 100644
--- a/mm2src/mm2_main/src/lp_swap/swap_events.rs
+++ b/mm2src/mm2_main/src/lp_swap/swap_events.rs
@@ -12,9 +12,11 @@ use uuid::Uuid;
 pub struct SwapStatusStreamer;
 
 impl SwapStatusStreamer {
+    #[inline(always)]
     pub fn new() -> Self { Self }
 
-    pub fn derive_streamer_id() -> &'static str { "SWAP_STATUS" }
+    #[inline(always)]
+    pub const fn derive_streamer_id() -> &'static str { "SWAP_STATUS" }
 }
 
 #[derive(Serialize)]
diff --git a/mm2src/mm2_main/src/rpc/streaming_activations/balance.rs b/mm2src/mm2_main/src/rpc/streaming_activations/balance.rs
index fa49f0a8d6..76f9d594e1 100644
--- a/mm2src/mm2_main/src/rpc/streaming_activations/balance.rs
+++ b/mm2src/mm2_main/src/rpc/streaming_activations/balance.rs
@@ -49,19 +49,32 @@ pub async fn enable_balance(
         .map_err(BalanceStreamingRequestError::Internal)?
         .ok_or(BalanceStreamingRequestError::CoinNotFound)?;
 
+    match coin {
+        MmCoinEnum::EthCoin(_) => (),
+        MmCoinEnum::ZCoin(_)
+        | MmCoinEnum::UtxoCoin(_)
+        | MmCoinEnum::Bch(_)
+        | MmCoinEnum::QtumCoin(_)
+        | MmCoinEnum::Tendermint(_) => {
+            if req.config.is_some() {
+                Err(BalanceStreamingRequestError::EnableError(
+                    "Invalid config provided. No config needed".to_string(),
+                ))?
+            }
+        },
+        _ => Err(BalanceStreamingRequestError::CoinNotSupported)?,
+    }
+
     let enable_result = match coin {
         MmCoinEnum::UtxoCoin(coin) => {
-            check_empty_config(&req.config)?;
             let streamer = UtxoBalanceEventStreamer::new(coin.clone().into());
             ctx.event_stream_manager.add(client_id, streamer, coin.spawner()).await
         },
         MmCoinEnum::Bch(coin) => {
-            check_empty_config(&req.config)?;
             let streamer = UtxoBalanceEventStreamer::new(coin.clone().into());
             ctx.event_stream_manager.add(client_id, streamer, coin.spawner()).await
         },
         MmCoinEnum::QtumCoin(coin) => {
-            check_empty_config(&req.config)?;
             let streamer = UtxoBalanceEventStreamer::new(coin.clone().into());
             ctx.event_stream_manager.add(client_id, streamer, coin.spawner()).await
         },
@@ -71,12 +84,10 @@ pub async fn enable_balance(
             ctx.event_stream_manager.add(client_id, streamer, coin.spawner()).await
         },
         MmCoinEnum::ZCoin(coin) => {
-            check_empty_config(&req.config)?;
             let streamer = ZCoinBalanceEventStreamer::new(coin.clone());
             ctx.event_stream_manager.add(client_id, streamer, coin.spawner()).await
         },
         MmCoinEnum::Tendermint(coin) => {
-            check_empty_config(&req.config)?;
             let streamer = TendermintBalanceEventStreamer::new(coin.clone());
             ctx.event_stream_manager.add(client_id, streamer, coin.spawner()).await
         },
@@ -87,12 +98,3 @@ pub async fn enable_balance(
         .map(EnableStreamingResponse::new)
         .map_to_mm(|e| BalanceStreamingRequestError::EnableError(format!("{e:?}")))
 }
-
-fn check_empty_config(config: &Option<Json>) -> MmResult<(), BalanceStreamingRequestError> {
-    if config.is_some() {
-        Err(BalanceStreamingRequestError::EnableError(
-            "Invalid config provided. No config needed".to_string(),
-        ))?
-    }
-    Ok(())
-}
diff --git a/mm2src/mm2_main/src/rpc/streaming_activations/disable.rs b/mm2src/mm2_main/src/rpc/streaming_activations/disable.rs
index ab1155378e..9643e9e652 100644
--- a/mm2src/mm2_main/src/rpc/streaming_activations/disable.rs
+++ b/mm2src/mm2_main/src/rpc/streaming_activations/disable.rs
@@ -8,15 +8,15 @@ use mm2_err_handle::{map_to_mm::MapToMmResult, mm_error::MmResult};
 
 use http::StatusCode;
 
-#[derive(Deserialize)]
 /// The request used for any event streaming deactivation.
+#[derive(Deserialize)]
 pub struct DisableStreamingRequest {
     pub client_id: u64,
     pub streamer_id: String,
 }
 
-#[derive(Serialize)]
 /// The success/ok response for any event streaming deactivation request.
+#[derive(Serialize)]
 pub struct DisableStreamingResponse {
     result: &'static str,
 }
diff --git a/mm2src/mm2_main/src/rpc/streaming_activations/mod.rs b/mm2src/mm2_main/src/rpc/streaming_activations/mod.rs
index c0a9bdf800..607876725f 100644
--- a/mm2src/mm2_main/src/rpc/streaming_activations/mod.rs
+++ b/mm2src/mm2_main/src/rpc/streaming_activations/mod.rs
@@ -17,9 +17,9 @@ pub use orders::*;
 pub use swaps::*;
 pub use tx_history::*;
 
-#[derive(Deserialize)]
 /// The general request for enabling any streamer.
 /// `client_id` is common in each request, other data is request-specific.
+#[derive(Deserialize)]
 pub struct EnableStreamingRequest<T> {
     // If the client ID isn't included, assume it's 0.
     #[serde(default)]
@@ -28,8 +28,8 @@ pub struct EnableStreamingRequest<T> {
     inner: T,
 }
 
-#[derive(Serialize)]
 /// The success/ok response for any event streaming activation request.
+#[derive(Serialize)]
 pub struct EnableStreamingResponse {
     pub streamer_id: String,
     // TODO: If the the streamer was already running, it is probably running with different configuration.
diff --git a/mm2src/mm2_main/src/rpc/streaming_activations/swaps.rs b/mm2src/mm2_main/src/rpc/streaming_activations/swaps.rs
index 3c3cb5d248..3d4aa2b93e 100644
--- a/mm2src/mm2_main/src/rpc/streaming_activations/swaps.rs
+++ b/mm2src/mm2_main/src/rpc/streaming_activations/swaps.rs
@@ -14,16 +14,19 @@ pub enum SwapStatusStreamingRequestError {
 }
 
 impl HttpStatusCode for SwapStatusStreamingRequestError {
-    fn status_code(&self) -> StatusCode { StatusCode::BAD_REQUEST }
+    fn status_code(&self) -> StatusCode {
+        match self {
+            SwapStatusStreamingRequestError::EnableError(_) => StatusCode::BAD_REQUEST,
+        }
+    }
 }
 
 pub async fn enable_swap_status(
     ctx: MmArc,
     req: EnableStreamingRequest<()>,
 ) -> MmResult<EnableStreamingResponse, SwapStatusStreamingRequestError> {
-    let swap_status_streamer = SwapStatusStreamer::new();
     ctx.event_stream_manager
-        .add(req.client_id, swap_status_streamer, ctx.spawner())
+        .add(req.client_id, SwapStatusStreamer::new(), ctx.spawner())
         .await
         .map(EnableStreamingResponse::new)
         .map_to_mm(|e| SwapStatusStreamingRequestError::EnableError(format!("{e:?}")))
diff --git a/mm2src/mm2_net/src/event_streaming/sse_handler.rs b/mm2src/mm2_net/src/event_streaming/sse_handler.rs
index 3fc1c5c333..3dfa6264d7 100644
--- a/mm2src/mm2_net/src/event_streaming/sse_handler.rs
+++ b/mm2src/mm2_net/src/event_streaming/sse_handler.rs
@@ -1,3 +1,4 @@
+use http::header::{ACCESS_CONTROL_ALLOW_ORIGIN, CACHE_CONTROL, CONTENT_TYPE};
 use hyper::{body::Bytes, Body, Request, Response};
 use mm2_core::mm_ctx::MmArc;
 use serde_json::json;
@@ -49,10 +50,10 @@ pub async fn handle_sse(request: Request<Body>, ctx_h: u32) -> Result<Response<B
 
     let response = Response::builder()
         .status(200)
-        .header("Content-Type", "text/event-stream")
-        .header("Cache-Control", "no-cache")
+        .header(CONTENT_TYPE, "text/event-stream")
+        .header(CACHE_CONTROL, "no-cache")
         .header(
-            "Access-Control-Allow-Origin",
+            ACCESS_CONTROL_ALLOW_ORIGIN,
             event_streaming_config.access_control_allow_origin,
         )
         .body(body);
diff --git a/mm2src/rpc_task/src/task.rs b/mm2src/rpc_task/src/task.rs
index 06f50e87da..3f5ceca1bd 100644
--- a/mm2src/rpc_task/src/task.rs
+++ b/mm2src/rpc_task/src/task.rs
@@ -21,11 +21,11 @@ pub trait RpcTask: RpcTaskTypes + Sized + Send + 'static {
     async fn run(&mut self, task_handle: RpcTaskHandleShared<Self>) -> Result<Self::Item, MmError<Self::Error>>;
 }
 
-#[derive(Deserialize)]
 /// The general request for initializing an RPC Task.
 ///
 /// `client_id` is used to identify the client to which the task should stream out update events
 /// to and is common in each request. Other data is request-specific.
+#[derive(Deserialize)]
 pub struct RpcInitReq<T> {
     // If the client ID isn't included, assume it's 0.
     #[serde(default)]