Update--
RackNRoad--
Apparently their tech that knew of the issue with Fords was out the week I had the cap installed. He contacted me to apologize for the problems, but they do not have the ability to hardwire the light. Per his prior experience, additional diode/resistor components are required for the hardwire, or the truck will also report issues from this.
RSI Smartcap--
Discussed issue with their tech support rep, who was familiar with the wiring issue. He told me they are working with the T-connector manufacturer to design a new one that works correctly. (BTW, the T-connector is manufactured by Curt Mfg. It's on a tag attached to the T-connector.) Replacement T-connector expected ~90 days out from now. The rep offered to pay for another shop to do the hardwire, or to put me on a wait list for the new T-connector once it's ready. I chose to wait.
The rep also said they are working hard on new locks for the cap that can be opened from the inside and also don't freeze in winter. He put me on a waitlist for those as well. No known time frame for those yet.
Finally, the rep said the top vent leaking was due to the dust filter being installed incorrectly. The leak happens because the filter needs to be pushed tight to the corners of the vent opening. Just need to open the vent cover, pull out the filter and push it back in with that in mind. I'll give that a try.
So, a lot of improvement hopefully coming soon. Still quite happy with the cap overall--it still seems very sturdy and looks great. I'll update as things happen.