I have a 2013 Y6 I built from kit. I have always found the PDB board ESC signal wires to be problematic. They are quite fragile. At one stage three of them broke off at the board. I managed to solder them again but they are close together and there are limits to my soldering skills. I see this as a disaster waiting to happen if one of these becomes dislodged by vibration during flight.
I am considering bypassing this altogether and plugging the six ESC signal cables directly into the APM. Is there a problem with this at all? It is obviously a little less convenient but the only functional difference seems to be that the APM will also be getting +5V from all six ESC BECs which wasn't happening before.