In theory, screen will absolutely add latency because it's another indirection terminal (your input has to traverse SSH, then SSH's terminal, then screen's term

In theory, screen will absolutely add latency because it's another indirection terminal (your input has to traverse SSH, then SSH's terminal, then screen's terminal, then your process, then back). Again in theory, that addition should be fairly small on the surface. In practice, and merely anecdotally on my part, I can attest that screen "feels" slower than a shell when I'm using it via SSH.