Erm, I was still going for the 5-step on1, on2, on3, rest, off note selection approach, only with another color/blink scheme for the added rest state. In that case the new chord-size UI approach is free for polyphony, including a polyphony of 1.
When you said that the used orange color for the base not was not an issue, I assumed that another color would be available. But I guess I misinterpreted that one?
We have the following LED colors:
With the orange-solid scheme reserved for the base note, we still have 6 colors left for a 5-step button. Wouldn’t this work? I guess some other colors are used already?