Hi, Crunch. I have not used an opto kill switch, ever, but the new planes, I put together, will have IBEC. I have a Futaba radio, that until now, I had set up the throttle cut, to shut the engine down, and when that wouldn't kill the engine, I have been using the choke. We used to have people driving their airplanes back into the pits, to their boxes. I believe that is a disaster waiting to happen. We request/require the planes be shut down out on the field, then manually moved to the pits. We have had 2 instances where the planes ended up in the pits, one happened to be mine, the other, the transmitter was shut down before the engine and reciever, both were roaming the pits looking for some meat! Luckly neither found any! LOL!!