A baseball? I couldn't even get one down the cuff of my boots!
Anyway, buckled (after they have dried out--I always take them apart after a day skiing and get all the components dry). Plastic has a memory, and if left unbuckled, the boots will "remember" being open and begin to relax. That means that when you put your foot in and buckle the boots, they will not as easily snug up to your foot.
JoeB, I'm curious as to your thoughts around packout early in the season... Can you explain a bit more about that?