Comment by KyleSanderson

The implementation is just wrong from what's been presented. basic jitter (20-100ms), and a dynamic payload size are what's actually missing here. The question now becomes though how interactive should your session be. Timing the connection latency might help to an extent, but this is about mitm and you don't necessarily know where your adversary is (first hop, or towards the end). Batching keystrokes would also help here.