Using the throttle trim to adjust the elevator brake compensation  like the Futaba FF9,.Using a multiplication on a high channel

The brake is applied with the throttle lever and puts the flaps down, this would cause pitch up on most model,  down elevator is progressively applied with this mix and can be adjusted with the throttle trim

Mix by Mike Shellim

A high channel is used; throttle  to channel 10

The next mix uses the throttle trim an input and is multiplied by the throttle setting, note the 300% offset

A curve is used to get even braking
to set apply full brakes and use the trim to get a stable decent, apply 3/4 brake adjust point 2, apply 1/2 brake and adjust point3, the same with 1/4
If you are real fussy use a 9 point curve

Elevator compensation mix added to normal elevator input, this needs assigning to a switch or flight mode