When reading/writing files, it's nice to have a garantee that note on messages can be matched with note offs. Optional function to generate note offs for hanging note ons, and deleting note offs for ghost note on messages.

I don't know exactly in what situation this occurred, maybe I powered off the keyboard while holding notes as a sharp casual end to playing - probably that should reproduce - anyways this is what happens currently, the notes stay held:

Related: should probably release held notes when exporting MIDI (at least, treat it as releasing the notes, i.e. include