Brake vs ESC Motor Braking, need Brake

Using rover 4.3, cube orange and an electric range rover (4wd version).

I have a vehicle that weighs 1700 pounds and has a foot pedal for a brake (attached via a big servo that is hooked up to the Cube Orange) as well as having regenerative braking. This vehicle does not support a reverse throttle command to cause the motors to work in reverse. ESC braking is not an option for it.

Regenerative braking was OK in the past but now I need it to use the “real brakes”. I do not see a way to assign a servo channel as BRAKE like I can for THROTTLE and the like.

I also want the Hold command to apply full brake as well, is there a way to make that happen already? It won’t do that now because there is no BRAKE channel (I assume).

Any help is appreciated!