I may have found a solution to the flickering and intermittent behavior of the X1 switch.
I recently BSTed an X1 v1 (spot). It's a cool little flashlight. Stealthy, silent, and surprisingly bright. The HA 1xAA form feels nice in the hand too.
I too have experienced switch issues - not only with flickering when using the momentary switch, but in an attempt to remedy the problem by changing the battery, I've discovered that some batteries simply didn't work at all in the X1! In particular, a NiMH batt who's "tail" (negative) was slightly squashed in. I can only assume that the "nipple" in the middle of the "piston" in the X1's endcap never made contact with the battery. I think that either the nipple or the piston itself is too short so that contact with a battery becomes intermittent. I am uncertain of the purpose of the little "feet" near the perimeter of the piston nor whether they are conductive or not.
One of the several attempts to improve the contact of the switch to the battery was to remove the "excess" wrapper on the tail end of the battery in order to expose more metal. This had little to no effect. Examining that same battery, the Duracell that came with the flashlight, and the piston yet again earlier this evening, I noticed that the tail of the battery was loose and was able to pry it off. I do not know if there is any glue to adhere the tail to the rest of the battery or if it is just the wrapper that supports the tail so attempts at removing the tail may vary.
Looking down into the tailcap at the piston, I dropped the battery tail with its nipple facing up - basically, resulting in more surface contact area. As of a few minutes ago and several battery swaps, including the "problem" NiMH batt, the flickering seems to have stopped and the X1 no longer requires a very tight squeeze for the momentary. And while the twisty doesn't have quite the same "snap", ie. doesn't require to be screwed down all the way to activate, it is still acceptable and responsive.
I'll, of course, continue to look for even better solutions to improve the behavior of the X1 switch, but in the meantime, we may have found a workable and easy solution.
73
dim