Not sure if anyone has said this already (too many missed pages and posts), but I talked to Sir last night about the "misfire" of the switch, and I think I may have an answer. If you've not tried it yet, Noalox the be-jesus out of the threads of the CAP, then twist the cap on several times without the batt in to work the Noalox into the threads, then put the batt in and tighten the cap.
Here's what I think my problem was (and maybe others). Once the cap is "tight", try and tighten it further (give it a good twist, the Noalox will prevent the threads from seizing), but don't twist so hard you strip the threads. I tried this, and the cap actually tightened a good 1/8 of a turn more. So far, I'm not having anymore "misfire" from the switch, and the mod functions as it should
I'll check in a bit and update.