You can capture Musescore with ActivePresenter (free) after capture you can add Biab tracks to it (Annotation Tab > Audio) then render to video.mp4
Biab will render the notation to video but if you want them all you will have to combine them in a free video editor or ActivePresenter may also do that (Annotation Tab > Video).
The _J140_OS demo was saved to musicxml then opened to Musescore, screen captured with ActivePresenter, then the Biab master render was added in ActivePresenter and the Musescore soundfont track muted (Speaker icon > mute).
You can align the BB audio track to sync by sliding.
If the sync goes out in a long video, select that video track then you can adjust the playback speed of the video by clicking the red runner icon.
I uploaded a Musescore.mp4 video demo.

This should all have been possible from within BBox alone ages ago.