@Matt69 , Do you need the additional PWM outputs to be connected via PX4? If not, perhaps connecting M0065 to a cpu uart and communicating directly would be the simplest (i can help you with that).
Do you have spare SLPI UARTs?
Not sure if PX4 would support multiple voxl2-io drivers running, i guess that should work? I don't think we have tried it. if you have spare slpi uart ports, just give it a shot? There may be a problem with two actuator drivers having the same name.
Alex