I made a small utility that'll replay socat log files captured by the -lf -x -v flags with the timing it collects if used in this way. It is very simple and is basically only there if you can't be bothered to roll your own:
https://gitlab.com/inivekin/socatplayer/-/releases
So if you're commonly doing a socat process like:
socat -x OPEN:/dev/ttyS0,b115200,echo=0,icanon=0 PTY,link=/dev/ttyO0,rawer 2> socat_log.log