A fast way to set both the root note and scale would be useful, allowing the user to quickly switch settings for a different song or a key change in a song. I’d suggest hold down settings and press a note. Long press to store current settings, short press to recall them. Perhaps it might be good to store the tempo and arpeggiator pattern too?
Also, a quick way to select the root note would be helpful. For this I’d suggest click+hold the second encoder and press the new root note.
Thanks for considering.