Anybody still hanging around this thread I have an update to my above post. I ended up going with a full Roadmaster setup. Nighthawk Tow Bar and Base Plates, and the Invisibrake System. Base Plate Install went fine. Lighting wiring went fine other than I found out I had a dead wire at my 7 pin at the back of the RV (blown fuse). That took me a bit to diagnose but got all that fixed. Invisibrake runs off the brake wiring, so it had to be right before I could get started.
Problem with the Invisibrake System and my truck, that I resolved maybe an unorthodox way.
Invisibrake is connected to the truck battery.
Part of the Chevy flat tow setup process is disconnecting the negative battery terminal to kill everything.
Well, the truck was still finding a ground path through the Invisibrake because some systems were still on, and my electronic parking brake would engage every time I would start towing. No bueno.
My solution was I just went and bought a cheap battery and put it under the back seat with the Invisibrake controller. So now the Invisibrake is totally isolated from the truck battery. And the Invisibrake will keep that battery charged as long as I have headlights on.
Now I still think with my truck "dead" - my power brakes aren't active. So I had to adjust the pressure up a little bit. On my first trip everything seemed OK, but I will be fine tuning it before the next trip.
I would have preferred to hook up the IB to the battery as designed, and just somehow disable the electronic parking brake, but I'll talk to my Chevy tech next time I talk to them.