It's more of a "just in case" thing for the most part... the actual risk of an escape as part of a sequence showing up over TCP without the rest for over a fraction of a second today is highly unlikely. That said, so many systems seem to add a delay well over half a second like we're using dialup.

I'd probably tune the delay to 100-200ms if I ever really felt it and have the option to change it.

The kitty key protocol solves this, but your app and terminal need to support it. Many do.