I'm not sure if this will help, but the ABS part of the pre-collision system can be disabled. I also have a 2020 F-150 that I want to use an Even Brake with so hopefully this may allow us to use them. Of course, we will have to remember to reenable the function when not being towed. Not ideal! Still a good idea to call Ford and Roadmaster to be sure it will work safely.
"How to Enable or Disable Automatic Emergency Braking"
The Pre-Collision Assist System cannot be disabled, but you can choose to disable the Active Braking feature.
From the Settings menu, select Driver Assist > Pre-Collision.
Toggle Active Braking on or off.
With Active Braking disabled, the Ford Pre-Collision Assist will notify you when a collision risk is detected but will not assist in braking to avoid a collision.
How to Adjust Alert Sensitivity
From the Settings menu, select Driver Assist > Pre-Collision > Alert Sensitivity.
Choose between High, Normal and Low sensitivity settings.
Note: High means earlier, more frequent warnings. Low means fewer warnings.