Great question, and all I can say is it really depends, I do think there's a really good amount of carry over from FMS to the exercises, but it really depends on the exercise and flaw. Couple of examples, overhead squat arms fall forward not that big of a deal, and I expect it from the majority of people. Heels want to come up off the ground or roll in or out, then that's a big deal and they have a bad movement pattern, that needs to be looked at. Not neccessarily stop them from squatting, but need to fix the issue.
Lunge, many will lose their balance, not that big of a deal, but lets say they their hips come way forward then that's an issue. So it really depends on what issue it is and where the tightness is, and look at it from a cause and effect relationship.