I have a very similar request and could be part of this idea. Some times, as an example, I am working on a song and I realize I want to change the key or I have not enforced the key for other reasons and now I realize I want to move all the notes on one note to a different note across all the events. So my suggestion is to be able to click the piano note on the left, in the edit window for the instrument and it would select all the midi notes on that note so they could be edited (length velocity, etc), moved or deleted all at once. This could involve a modifier key if necessary to differentiate from clicking the note and selecting the midi across all event on that note.