? on dual pcb in ascii ft

Got a ASCII (flash clone) with a sony pcb. has the 5v-3.3v converter on it but i wanna re do the wiring and make it dual pcb. I’m gonna be using a nubytech ps2 controller and later version Madcat 360 wired. I was thinking that since their sharing the ground and voltage it shouldn’t be a problem, or use the converter between the 360 to ps2 so the 360 voltage is downgraded but i wouldn’t know if that effects the pad when playing on the 360.