Ornaments should be able to attach to individual note of a chord
Currently, when entering ornaments, including the trill line in Lines palette, these objects are only attached to top of a chord, not individual note. This sometimes makes things confusing, especially for playback and braille transcription. Sometimes it seems that the trill will apply to all notes of a chord, but sometimes not. in Bach's Sechs Kleine Praeludien (https://musescore.com/user/13033246/scores/5743221), the first rh chord has the mordent on C not E, but Musescore will force both to be affected, and in braille, it's placed before the whole chord too. In full scores, when two or three instruments form a chord in a staff, the every note should have a trill attached, to avoid confusion. So there are plenty of cases where ornaments should be placed on certain or all notes of a chord. Musicxml supports this kind of thing, by placing
<ornaments> inside single
<note> element. In Musescore, the ornaments and trill line should be placed on individual selected note(s).