Hi! I firstly wanted to say I have been looking forward to Stella for a while and can't wait to hear more updates!
I just had the idea if it was able to play chords by pushing a button that your left hand can easily reach like a button to tell the instrument to play a major chord or a different button for a minor chord, 7th chords and diminished chords. of course there is still more types of chords but I think if the instrument had the option of 4 buttons play a major chord, minor chord, 7th or diminished it it could be really innovative with just that much. Like you could be soloing and you want to hold a note out but make it a chord so what ever note you play could be the root and you press a button and the trumpet will also sound the 3rd and the 5th with the same technique that you are using to play the root.
Would love to hear back from you and your opinion of this idea and how it could work if you were interested in this!