It's late, but I took apart the GP-SS switch tonight and it has me fascinated. This switch is so sensitive it's friggin awesome!

Details to follow.
First of all, with the nut firmly screwed on (I mean trying to tighten with a screwdriver with forceps trying to hold the nut firmly), the post definitely protrudes above the nut. It is on as tight as it will go. No question. Perseas, I see what you mean about dremeling the nut so that it goes down a little further down the post.
The thing that fascinates me the most is that with the locking mech fully closed against the switch, I can set the GP-SS upright on a wooden table and it will not fire. If I set it on my mousepad... it fires fully as if I'm pushing down the button with my pinky!
If I set it down on a piece of paper sitting on my table, no fire.
If I set it down on a fresh piece of paper towel.. guess what? Full fire! Vapor galore! People, that's how sensitive this switch is and it's also what makes it the best bottom button I've ever seen.
Yeah it might be a fraction of a millimeter off where it should be since my Lux doesn't fire when I sit it on a mousepad or paper towel, but it's cool. My fix is just keep the locking cap a quarter turn from closed and I'm good. Besides, most of the time the GP-SS is on its side anyway.