I think as far as topper issues goes, I've noticed that some of my toppers are actually 'crooked' themselves. They sit funny on my provari also, and eyeballing them while not on a mod seems to confirm this. That said, I think some people reported the crooked atty issue on the cana could be fixed by tapping the 510 down? Not sure, maybe someone while chime in
Mine is crooked, there is not doubt. I have about 15 devices and my Kayfuns sit straight on everything except my cana. Honestly though it doesn't bother me, just wanted to point it out. It is only noticeable on taller toppers. It's not crooked enough that you really even notice with a dripper installed.