I have built a basic 2 player 6 button control panel we 4 buttons on the front, 2 for player 1 and 2 for player 2 (coin and player 1 or 2 button).
I have 2 x Xin-Mo USB encoders, one for each player and they work fine both can add coins and use their player buttons.
However I have bought a bartop kit and it only has 3 buttons on the front, a player 1 and player 2 button and 1 coin button. I can’t cut another hole (long story) and wondered if I can use a combo key for player 2s coin button? O maybe there is another solution.