Shortest 1x18650 Tail Clicky Mod Friendly Light or Host

I’m in the search of my perfect EDC, and I’m looking for the most compact mechanically switched 18650 light. I would like to be able to drop in a FET driver w/ Bistro, and be able to swap LEDs without needing to reflow emitters. The other requirement is for a deep carry pocket clip, either S2+ clip on style, or bolt on.

I would prefer single emitter, though I understand that I can likely get shorter options via a triple/quad route. Currently the shortest 18650 clicky I have is the S41S, followed up by the E2L. The Folomov 18650S looked promising, but they use neither standard star nor driver, so that’s a no-go.

Any suggestions?

You can try to do this kind of mods using 18500 tube or chopping the light: