The spring loaded switch om my 10CAP I use it for smoke, easy to get from the throttle and I just release it to stop the smoke.

When I started flying jets we were running out of chls all the time, I learned to use a servo for two functions, a good example was the retracts servo, it was also used for the brakes, pushing a spring loaded mini valve like the one I posted earlier, the servo will go over center and since the valve was not been pulled or pushed at that servo arm position, we installed a valve so the servo arm could push it to brake the aircraft, turned on via a different switch mixed to that chl.