So if I'm understanding this correctly... What this does is, it's like a breakout power supply (getting power from the CPU), then you mount that under the playfield somewhere, and then you grab a switch from the playfield (whatever you want to do an action), and that feeds power to lights, or anything within reasonable voltage. This is instead of trying to power off of the playfield wiring (which is rated for what's already populated there, and adding something would strain the circuit. Is it JUST running off of 12v supply?

I can see lots of potential for this. There are strong 12v motors that could do some neat motion