Yeah none of those OEM plugs are wired to do much more than control lights on a trailer and power brakes.The reason I asked how you were getting power to the camper was that the Ford Super Duty trucks (I realize you're in a RAM) aren't getting much current from the OEM 7 pin. The amount of current is maybe enough to maintain the batteries SOC, but unlikely to bring the batteries to 100%. The workaround there is to run a dedicated wire from the truck battery to the DC-DC charger. That will give you more current to work with.
The biggest problem I have now is getting enough information about DC-DC charger output and alternator performance to make a good decision on what to do next. I could run another set of wires and add another Orion-TR. I could also upgrade my alternator or add another one.