Matek 405-Wing S2 Port question

[chucky-whiskers]

I have a pan/tilt gimbal I wish to use with a head tracker. I'm using a r-xsr receiver, so no pwm outputs. Airplane has 2 ailerons, 2 flaps (using y cable to use fewer outputs from FC), 1 elevator, 1 rudder, 1 motor. The FC has 8 servo signal outputs including 1/2. Is there any reason I can't use S2 port configured via variable throttle setting and use a different radio channel output for the signal input on that channel to use it as a servo signal output port? I really want to be able to utilize that empty port in future iNAV versions if it isn't currently possible.