Yes 2x battery mods are what I,and sure most of the vape community have moved over too. It's amazing that we still see these companies try to reinvent the dual 18650 mods knowing dual 2X battery devices are out ??I had luck with my door, only 1.25 turns loose on one screw, after a few weeks of use, and no loosening since. My thoughts are that the looser it got before tightening, the more wear on the threads. It really isn't the greatest design for a closure, as I feel with the fill port as well. I could see not using a rivet for replacibility of a broken door, but then why make the door out of plastic in the first place. It almost screams aftermarket upgrade, but for such a niche, why bother. I am considering the carbon, but I think I'd rather spend the money on a Kickstarter for aF support, as I'm invested in 2x700 batteries, and only see a 200w carbon, if I'm not mistaken.
Maybe they will wake up one day. I know 18650 devices are smaller but 2X battery devices have that step up over the 18650.