My hens are going gang busters 3-4 a day with 4 hens we have one that pecks the air sac side of her egg. I know which one it is and she is very low on the totem pole
though she has never broken the membrane but every couple days it’s cracked, they have a dedicated oyster shell feeder and I sprinkle some on the ground. We put up curtains over the nest boxes last week and it reduced the cracked egg. She is also the hen that lolly gags in the box I bet she goes broody