Can I ask you how is the feedback when you write on your keyboard? Isn't there a delay?
That's kind of my "oww, server is too far away" point with SSH...
FWIW, that's what the default keybindings configure.
You can create your own input.conf to override this - ^F for `audio-delay`: https://raw.githubusercontent.com/mpv-player/mpv/master/etc/...
You can also specify --audio-delay (^F in https://mpv.io/manual/master/) which accepts fractions of seconds, but that makes for much slower iteration.