Explain the odd transaction_status_sender.is_some()

unified-scheduler-pool/src/lib.rs

@@ -449,10 +449,17 @@ impl TaskHandler for DefaultTaskHandler {
             BlockVerification => vec![index],
             BlockProduction => {
                 let mut vec = vec![];
+                // transaction_status_sender is usually None for staked nodes because it's only
+                // used for RPC-related additional data recording. However, a staked node could
+                // also be running with rpc functionalities during development. So, we need to
+                // correctly support the use case for produced blocks as well, like verified blocks
+                // via the replaying stage.
+                // Refer `record_token_balances` in `execute_batch()` as this conditional treatment
+                // is mirrored from it.
                 if handler_context.transaction_status_sender.is_some() {
-                    // Create empty vec with the exact needed capacity, which will be filled inside
-                    // `execute_batch()` below. Otherwise, excess cap would be reserved on
-                    // `.push(transaction_index)` in it.
+                    // Adjust the empty new vec with the exact needed capacity, which will be
+                    // filled inside `execute_batch()` below. Otherwise, excess cap would be
+                    // reserved on `.push(transaction_index)` in it.
                     vec.reserve_exact(1);
                 }
                 vec