I have another problem here, I tried to find a solution and I couldn't. Maybe it's very easy.
I'll simplify the examples to make it clear.
I have a line in a PianoStaff (actually it's for Harp in the original) and there is one single chord in the upper staff that is bigger that has some notes more suitable for the lower staff, with a bass clef. It's hard because \autochange and \change Staff DON'T work just for half of a chord, just for the entire chord. Ah, in this measure there is nothing in the lower staff.
Is there another command that could split the chord between the staff in an optimal way, so each staff gets the more appropriate notes????
I tried with \autochande and ]change Staff. I will paste the two simplified examples: