> https://lifeofpenguin.blogspot.com/2021/07/sheet-music-in-gnu-emacs.html

That is interesting.

Are there programs to convert other musical notation files
into this Unicode format?

I'm not aware of any such program. But with an active W3C Music Notation Community Group , I expect to see more of this in the near future.

Can it handle rests, dots, ties,
bar lines, and so on?

Complete symbol reference is available here. http://www.smufl.org/files/smufl-0.9.pdf