I don't pretend to know the answer to any of this but here is my experience... My TV is a 2016 F-250 with the integrated brake controller running the binders on our Flagstaff 8528IKWS. We've had this rig for about 8 months and almost 5,000 miles of travel throughout the SE USA. Florida flat to Blue Ridge mountains, highway, city, etc.
I initially tried to adjust the gain settings like my previous experience with a Tekonsha P3 to lock the trailer wheels at 20mph but it never happened. I settled on a "that feels about right" braking result after some trial and adjust stops. That means to me that the rig stops the same as just the truck when using equal pedal pressure.
This has worked fine for me but left me with a bit of self-doubt until I got well tested on our last trip. I follow other vehicles at a conservative distance but had a yahoo slam on brakes to make a turn off a 2 lane highway with all of us traveling about 50mph. I also slammed brakes and the trailer tires made a quick "chirp" followed by the usual well-balanced braking of the rig. This confirms to me that the gains are good and that the Ford controller is doing a great job of regulating the braking signal based on speed and g forces of the deceleration. I no longer am concerned that I can't lock the trailer wheels at slow speed.