Just wanted to mention...
Earlier last night I accidentally cross-threaded the tailcap when putting it back on my L2p. :fail: It was seized up pretty hard. I had to wrap the tailcap and light-body in electrical tape and use pliarz to get them apart (trying to be gentle in the process).
Found out that the body threads were fine but the tailcap threads were boogered. I eventually brushed them out and ran a flathead screwdriver through them and they fixed up beautifully and it's now threading in nice and smooth and it all works fine.
What I wanted to say though;
While assessing the threads on my L2p body, I checked to see if my Coast 7736TS tailcap would thread onto the L2p body. And it does. Perfectly.
The Coast 7736TS tailcap is a forward clicky switch, and it mates up and works beautifully with the L2p host.
I haven't pulled apart the 7736TS's tailswitch yet to look at it; but you might consider at least that it works and that there may be some options there for what you're doing here.