About the joystick selection tool permission issue, I'm waiting for a new Xinmo interface shipment before pushing further. Once I have it I will try again. I have a 4 player board on my arcade. I would need longer GPIO cables to follow my initial plan to connect player 3 and 4 on one Xinmo, but those cables come from China and seem to be out of stock due to the disruption of global value chains.
I hope that the Joystick selection tool will allow to connect P1 and P3 on one Xinmo, P2 and P4 on the other (considering cable length), then reallocating the players with the tool. If I can make it work.