That has not been an issue. The boot settles into place nicely due to the shaping of the baseplate. Even if you prefer to loosen all of the strap adjustments (there are a lot of ways that riders are using the NX2 models) there is a natural point when you will simply feel that you are "in".
This depends heavily on your shoe size, apparently. It's safe to say flow didn't test either the medium or large on size 8 boots. I am having that issue as I said, and it results in heel lift in the binding.