From my reading, the only Ford Maintenance needs to be doing is checking the strength of the coolant every 10k miles (using 20+ year old simple bulb tester?) otherwise leave it alone and sealed.
Since your out of warranty, lets think about something else ... I assume your app shows 100% but you get in the truck and the screen shows 85%, is this correct?
I have no idea ... I have gained confidence in my dealer and I think I would tell him that I disconnected the battery and the resistance was gone ect.... That you think it is either the motor or sensor within the brake system...??
I hope you are still in the 3 yr 30k window?
It seems...
I have used one at the same location several times the last two summers. When the adaptor comes out with my first attempt I use it, when it refuses, I use my own adapter. Speed was just the same with or without it at the Boardman Sage Center location.
You indicated you usually drive one-pedal, as do I. I use the brakes sparingly and worry about disk rust because of where I live, so I drag brakes using both pedals occasionally ... could rust be causing your issue?
I have the same truck, same mileage, and the brake pedal has always seemed smooth and the feedback pressure normally proportional. No "breaking through a thin sheet of ice " feeling.
What coating can be applied to protect the unpainted steel under a vehicle? I have watched videos for Por 15, and a few others, but most are not shown coating a truly rusted area.
If you want to keep your Lightning in great shape for the next 6 to 8 years, what can you coat those items...