I wouldn't say you're SOL as long as you have the rest of your guidance system working. In that situation you know you are going to have a dead stick landing, you just fly out the remaining fuel in the tank at a safe altitude and land when the engine stops making so much noise.

The optical kill switch allows you to remotely shut down the ignition system on your engine at your will. It also will shut down the ignition system if your receiver looses contact with your transmitter to keep your plane from flying off into the next state.