When it must be inbalanced due to the number of eggs, as long as the extra weight is towards the hinge then it retains the safety benefits of being balanced.

Since I get eggs while holding the carton I tend to take from the ‘outside’ row first, starting at the ends, and work my way into the center by the hinge. This puts the weight in the hand I’m using to hold the carton and works well even for 18 and 24 count cartons. If I set the carton down before yoinking eggs, I would go for more balance.