So my V6II Cactus trigger just broke. Turns out the power switch is garbage. While I was fixing the power switch I figured I would try fixing the loose fitting shoe mount. I found that the screws in the mount are too loose and that once apart I could access and tighten them. This solved my fit issues.
I wrote a quick post about it here if you want to see the pictures.
http://brett-martin.com/2017/12/12/fixing-the-cactus-v6ii-flash-transmitter/
Unfortunately after seeing how the power switch is constructed I don't think I can keep using the Cactus system, even though I just got HSS working.
Going to try out the Godox system as they have a huge range of options from a tiny on camera flash to huge monoblocks that all work with Fuji.