You can set the Parking Aid off, but it will come back on again next time you twist the key.
But some progress:
I confirmed that a trailer with electric brakes would be recognized and would turn off the Parking Aid. I had no luck trying to fool the brake controller with any resistive load down to 1 ohm. However on '12 or so and up trucks, there is a setting in Settings>Driver Assist>Trailer or thereabouts to allow selecting Electric Over Hydraulic brakes instead of Electric. With this setting enabled, I was able to consistently fool the brake controller with a 100 ohm wirewound resistor. Less would probably also work, but will dissipate more power when you brake (because the controller will drive it like it is brakes). 230 ohms did not consistently fool it, 470 ohms never fooled it. With a 100 ohm there are occasional spikes of current (about 110 mA) that seem intended to look for a trailer.
I plan to wire a 100 ohm 5W+ wirewound resistor between the blue and white wire on the camper's 7 pin receptacle. Then when I plug in the camper 7 pin, it should recognize it as a EOH trailer and shut the Parking Aid off. Unplug it, and it is back again. The only inconvenience with this method is if you actually do pull an electric braked trailer without the camper you would need to remember to change the brake type back to electric.
