I had Pullets doing the same thing! What the heck. Before I joined this forum, I researched this behavior. The pullets are maturing rapidly and require increased Protein in their diet. But, be careful about too much Protein because like humans, it can cause kidney issues. Fix one problem and cause another. I fed mine Cat food... yes, Cat food. Its Very high in Protein. I bought small bites and added a little water to soften it up. They Loved it. After a few days the feather eating stopped. Then it happened again. Then I gave them more cat food. I also went fishing and gave them fresh fish guts ( high in protein) they LOVED THAT. I offered them Sardines, tuna, scrambled eggs and night crawlers too. And guess what? Boom!!! Problem solved.
I did use "Pinless Peepers" and the googlie eyes on one Pullet only because she was pecking another to death. Not pulling the feathers and eating them. The protein is what fixed the feather eating problem. And I switched Feed. I use to use what you are using.