The Teknic NEMA 34 brake appears to require 0.41 amps so fan2 might be usable.
https://teknic.com/products/spring-applied-power-off-brakes/NEMA-34-brake/
; Z break M950 F2 C"nil" ; disable fan 2 and free up the associated pin M950 P7 C"fan2" ; create gpio pin 7 for Z brake using diode protected fan2 output M569.7 P0.5 C"fan2" S20 ; Z drive 5 to use fan 2 output control the brake with 20ms delayThanks!