Hi,
Would it be possible to replace the potentiometer on the thruster commander with a fixed resistor in order to turn on and off the thruster with a switch?
If your just asking BR, ignore what I say, otherwise the answer is yes.
Hi @Nathan1, welcome to the forum 
If you only want a single thrust level you can use a pair of fixed resistors in a voltage divider, with a switch connected to the “SWITCH” input to allow turning on and off.
If you’re specifically after full throttle you can use a jumper to the 5V line, instead of the two-resistor voltage divider.