The Rn, RN, and RR roll types are great musical features. It would be nice to be able to have the notes in the roll conform to a scale ex. ascending roll in C Major, descending scale in A Pentatonic, etc.
This could be determined in the system settings as discussed here: Musical key and scale lock toggle for +/- buttons
It could also be interesting to have this work like the arpeggiator, and a have MIDI chord in the 2nd FX Slot determine the notes for the roll.
What is the problem?
Cannot have a roll conform to specific notes, scales, etc. Always chromatic.
What do you want to achieve?
Use rolls with specific notes/scales.
Are there any workarounds?
No.