Changing PWM Outs

Hello,

I’m trying to develop a modular drone framework based around Pixhawk. Is there a way to change which output controls which motor/actuator? e.g. change the X-Quad config such that MAIN2, MAIN4, MAIN6, MAIN8 control motors instead of MAIN1-4. How would I go about implementing something to make this automatic, such that when the user connects 4 motors to a physical central interface the software automatically decides which output corresponds to which motor based on the geometry of this interface?

Thanks

Anyone have any pointers here? Who should I contact?