A "Kill Switch", whether it is the form of a "fuel interrupt" (Line pincher - hardly EVER used anymore), a "flood carb" (Choke servo- operate to close venturi), or "elec kill" (either a switch operated by a servo, or an electronic module that switches off the igntion battery using solid state current control like an ESC, or a relay, like this Dim Eng stuff) are, in my mind, the IMAA (for whatever that is worth) and the good ol' common sense guys who are concerned about safety ---- NEVER a Luxury, but rather, an essential part of flying an overpowered gasser with a direct, solid, throttle pushrod to a hard mounted motor.

The rationale is that throttle servos fail. It has happened to me before. Sometimes fails LOW, engine dies, sometimes fails HIGH, full throttle, and that ain't good. Most of us carry fuel that would exhaust batteries before the tank empties. Most 3D type airframes these days are so grossly over-powered that they likely would not tolerate or survive an extended mission at full throttle, all other things being equal.

An engine-stopping device operated by the transmitter solves that issue. Had a flight the past summer where the throttle pushrod had stripped...couldn't idle low enough to land. Without a kill choke (on that airplane), I would probably still be flying around out there just a notch above idle, staggering through the wind.

Whatever device you decide to use, to many of us, a "kill option", is not really a luxury, it is simply another safety component that we want to have on board to keep things relaxing. (There is a LOT of tension and stress involved if you have a throttle servo failure)