Very impressive topic here. I just discovered it and am following with great interest. I can see both sides of the 13 vs 12 question. So nice to have the general flexibility to go either way / both ways!
I found a picture of the aforementioned optional C key, but I don’t understand it. (Note: I don’t have my Morph yet). Is this another sensor area on the side of the unit instead of the “top”, or is it an on-top key that isn’t necessarily a note, or what?