Retropie was built for the pi and will be most compatible with that. It’s likely you’ll run into hardware/software incompatibilities with a board none of the developers own. Personally I don’t even think we should have the n64 be part of retropie because of how many issues we have with it. I would just recommend using a PC for more powerful systems like the n64. Not that you cant try using the cubie board but expect it to have issues.