Hi
I am just chiming in with my 2cents. I have been in this position and trying to sync video with external audio. There was no real way to do this nicely as the audio will stutter etc.
Upon asking here about 6 years ago, I followed the advice and edited the video(s) together so it is just one "super" video.
Easiest way to do it even if it requires setting aside some editing time. Your edit is not a big ask and it is the simplest way out of your issue.
Kinda the only way to ensure sync tbh.
Eamon