I have a clip on plug energizer - but it's connected to the panel on my flight box with three feet of wire (and a "zinger" string retractor reel clipped to the flight box to keep the wire out of said prop). It stays on until I set the starter motor (also wired to my flight box panel) in the top of my flight box and walk around to the rear of the wing. Being on the 7A 12v gel battery there's no worry I'm going to run out of juice letting it stay hot while I take my time. The meter on the panel also gives me a visual that the plug is OK and I can adjust the voltage up on cold days.
Just never got out of the habit of a wired glow-driver from my free flight & C/L days with a big 1.5v dry cell.
I have a constant bearing with decreasing range---what do I do now?
Flood tubes 1 and 2, make revolutions for 14 knots, set safeties for 2,000 meters, match bearings on scope and fire tube 1, fire tube 2.