You are pprecisely correct it would be easier to get a plug and play light
converter and plug it in.
You would then be limited the the lesser weight
since the higher weights are predicated on the electronics detecting the trailer and stabilizing the entire system electronically. I believe if the Ford system is used and perhaps the GM well the on board sensors detect the yaw, roll, and accelerations etc and the car's CANBUS controls are compensated for towing. This has been required since 2005 in Europe along with checking those pesky trailer bulbs. This is the reason the tow limits are higher there and not the lower speed limits, smaller pounds etc.
The newer trucks are equipped with this technology and I think that Ford required for the higher towing limits that the package be factory installed and the computers adapted for it.
The computers and modules can, perhaps, be added after delivery, but you would have to ask Ford. I am familiar with the VW system and it can be added later and the computers programmed to function with the module and lights
In the case of the VW (I don't know about the Ford or GM) the electric power steering will also give steering cues for the proper reaction to incipient trailer sway.
These systems are becoming very sophisticated today.
There are also trailer mounted stabilization systems available that brake individual wheels on the trailer as well. If you search for videos you can find several.
The easy way is not necessarily the best, but it is each individual's choice.
Bob, where you always advocating to follow the factory recommendations this is a major part of that now The lower limit is to be used without the proper electronic components and wiring. In the case of the Escape
(I can't speak for the transit since it was not on my list of possible new tow vehicles) the limit is 2000 lbs without the factory setup (this means mostly the wiring kit and modules with the computer activation's as required whether factory or dealer) and 3500 with. Of course this would mean a brake controller as well. I don't know if the factory brake controller option ties in with the onboard computer, but it might as well.