Pretty sure you don’t need to worry about pulleys type. Majority of the boards today use 5M, adapter type/side of the pulley is what might be different, but that is only restricted by the wheel core, not the board you have. As long as the pulley fits into the wheel it will work.
The thing you have to figure out is # of teeth on the pulley because if it has more than your current setup, you’ll might need new belt if the motor mount doesn’t have enough adjustments.
@AlexB below has a backfire zealot pulley, cloud wheel website says zealot uses 605, exway flex uses 606 (44t). Any idea what the difference might be/if they’re compatible?
I have a message in with Cloud wheels to see if they can tell me the difference. I would guess maybe a spacing thing (how deeply inset the pulley bearing is maybe) but who knows.