Those molting birds just go through a lot to get those pins pushed through and start their new feathers. I had a couple that stayed on the roost for a couple days and I actually was pretty concerned for them and then.... Feather explosion the next day. It's hard to see them like that.
One thing though, and I saw it for my birds again this year is being strict on the formulated feed. Giving meat scraps when available and clean fresh water with electrolyte boosts once or twice a week.
I've had a hen that contracted blackhead but it went full blown only because she was molting. Her immune system was down putting energy into feathers. So doing everything else impeccably becomes 10x important during the molt.
I lost a different leghorn to molt this year. She just kind of sat down and gave up. She wouldnt eat or drink and just wasted away. I moved her to her own pen and gave her water and tuna and she wouldnt even that.