Here is another potential request related to the piano roll, coming from the discussion of Introduce chords as musical units :
@abraxa wrote:
Additionally, the chord track could allow making use of music theory principles easier if it was tied in with the piano roll. Setting a key and scale in the chord track could allow the piano roll to not only highlight the notes associated with this key and scale but also assist in the creation of chords as it now knows what range user is working in. Ableton’s piano roll folding and the circle of fifths come to mind.