With recent optimizations a single thread to write data works just fine.

Author: Christian Wischenbart

src/StreamDeckSharp/StreamDeckHID.cs

@@ -90,7 +90,7 @@ internal StreamDeckHID(HidDevice device)
                 keyLocks[i] = new object();
             }
 
-            var numberOfWriterThreads = NumberOfKeys;
+            var numberOfWriterThreads = 1;
             var numberOfReadThreads = 1;
             var numberOfThreads = numberOfWriterThreads + numberOfReadThreads;