I'm the happy owner of an mk-v nexus sled. 2" 4 stage post with gen2 electronics. I fly the bottom battery rack inverted, and until recently I have been very happy with the decision to do so. I recently disassembled my sled, and since reassembling it, I cant seem to get the bottom electronics to screw on quite tight enough to the post. This has resulted in a few degrees of horizontal wiggle in my battery rack. I have yet to notice it cause vibrations in any of my shots, but i fear if left unchecked, it could lead to some. I fly a pretty fast drop time anyway and as a result it hasn't thrown off my side to side balance, but it definitely would be an issue with a slower drop.
It seems like the easiest fix is to switch back to flying un-inverted, I know a lot of nexus owners fly their sleds inverted though, so Id love to hear what you do to avoid the issue. I feel like I could get a wrench of some sort in to tighten it more, but i don't want to get the screw on ring too beat up, or risk bending it. I rarely disassemble my sled, but Id like to keep the option to, so I would prefer to avoid lock tight.