With the loss of JACK support in the forthcoming Musescore 4 (and JACK already hasn't worked on Mac since 3.4), there will be no way to sync a video with playback. (https://musescore.org/en/node/334701#JACK)
This is obviously a vital feature for anyone doing soundtrack work, and is a given for programs like Finale, Sibelius, Dorico, and Logic.
I know there are other feature requests along this line, but they're all from several years ago, and the answer always seems to be "use JACK".
I really don't want to get stuck at 3.4, especially with VST support coming in for 4.0 (which will be a game-changer once expression maps are sorted).