Support for spinners is available. You need an extra PCB that plugs in the multi. I didnt want to delay the project anymore and make the final multi more expensive, so people who need that PCB because they want to play with spinners, can get it from
@Mitsurugi-w.
Even I have installed a pin for 10/12Mhz. This pin will be a "1" if the game runs at 12Mhz and "0" if the game runs at 10Mhz. If someone is a bit purist, you have a pin there to run each game at the right speed. The clock is located in the A Board, so some soldering is anyways needed. I will not offer a clock PCB that plugs into the A board, althouhg it should be pretty simple to implement a small PCB with 2 clocks that plugs into that pin for choosing the right one.
Right now, I see no limitations, but rather endless opportunities, like converting games to work with the multi or making trainer versions, or....