Would like to specify letters such as “R” or “L” or other letters for fingerings, instead of just numbers.
(I would use it to specify which hand plays a note, whether in dense single-staff keyboard writing, or in percussion writing.)
(I realize this can currently be achieved by creating text on each note, but that feels like a hack solution, considering there is already support for note fingering text.)
Fingering conventions are different on many instruments. Defining an R fingering on a violin might cause some consternation. Terms like LH and RH are available as keyboard playing techniques (you can define your own, if you want). These are not ‘hack’ solutions, they are established parts of the music lexicon.