I've seen multiple people recently say to not do the float test. If the eggs are far enough along and they've made a small pip in the shell you could drown the chick.There is a sticky here that says to do the float test to see if eggs are viable. There is so much conflicting things in here. Can chickens lay bad eggs?
I have one hen who lays an egg like that. I don't think it is related to her bottom being bald. Some hens will pull their feathers out if they get too dirty, I had a hen with diarrhea and she got those feathers caked with poo. She wouldn't let me help. A few days later, she pulled out all those dirty feathers. They will come back after she molts.Another question for you. I always get an egg that looks like the pic I uploaded. Suspect it's the same hen who is bald on her bottom some reason the feathers won't grow back. View attachment 1140046