I was hoping to see it working in this state before ordering the button. Not sure I'm confident enough to take the steering wheel apart to put in the new unit.probably they have the same PCB, but transmission is via LIN, so there must be some logic element which translates buttons to LIN commands. question if it is reprogrammed chip, or maybe adding missing components to the PCB you will get operation also of left top button way you want. anyway, worth it, cost of buttons is around EUR60 for Giulia, EUR 70 for Stelvio and you get proper button with icon etc.
Note, that I tried similar trick with Keyfob to activate remote start - got RS programmed into proxi, got my fob opened and added microswitch - it did not worked. getting US keyfob for the car worked.