[a11r]

This is indeed the right way to leverage TCP flow control, and works well at the layer that knows exactly what is coming over the socket. The pitfall here is if semantically independent data is being multiplexed over the same TCP connection then suspending reads may cause collateral damage and in the worst case livelock situations. Examples of multiplexing include separate streams and control frames in HTTP/2, in-band health checks and keepalives in various protocols, etc.