> have users manually upload midi with a proper score attached to some store or community repo with user reviews. It's less satisfying as a solution, but it means all it takes is one motivated user for everyone to enjoy the score.
Musescore already has such a collection of sheet music https://musescore.com/hub/piano so it'd also be possible to allow users to import from there, going from sheet music to midi instead of trying to reverse the process.
Yes, but then you would still lose quite a bit of information. Besides that, musescore is pulling a bait-and-switch on the user generated content that makes gracenote look good.
Musescore already has such a collection of sheet music https://musescore.com/hub/piano so it'd also be possible to allow users to import from there, going from sheet music to midi instead of trying to reverse the process.