Cool, thanks again for easing my mind!
Lug nut thread engagement must be >= lug diameter, correct?
No worries. This ranks pretty much right at the very bottom on my scale of 'should I be worried about driving after doing this".
As for the thread engagement, you've got it. In our case you'll want at least 12mm of engagement as we run M12x1.5mm studs. Theoretically this would require 8 full turns (12mm/1.5 = 8) at minimum to get the necessary engagement. If you've got an open-ended lug then it's pretty obvious if you've got proper engagement but if not then just mark one side of your lug(s) and count the turns.
