What's the best way to go about putting a switch activated Servo on the Betaflight F3 FC? Go through the board? Or go through the receiver?

I just want to Servo to move when I flip a switch. I may use one of my PPM receivers, because my sbus receivers seem to be having range issues on a previous set up. I haven't determined if it's a firmware issue, or, a glitch in the hardware.

Just need to remap a motor port to a servo port & assign it to an aux channel
Here is Oscar's guide on pin remapping: https://oscarliang.com/betaflight-resource-remapping/

Have a read of this article over at the Betaflight Wiki: https://github.com/betaflight/betaflight...LT-for-3.1

Using a PPM receiver is likely to limit your options.

Range does not have anything to do with the protocol that the receiver uses to communicate with the flight controller, so if you have an SBUS receiver that has poor range compared to a PPM receiver and they both use the same radio system, then you either have a damaged receiver or (more likely) poor placement of the antenna(s).