Thank you so much to everyone who responded!
After the comments about my Favorelles beard, I started keeping a closer eye on that. In 3 days she went from no beard but had neck feathers, to naked under her neck, to naked strip from under beak to the top of her chest! So I started worrying that she was the victim rather than the aggressor.
In the mean time, I added some clutter to the run and upped their protein. And - the pecking and feather damage seems to have stopped! Yay!
My theory is that Ginger (Faverolles) actually started this. She is the only one whose back feathers aren't damaged and she was observed pecking all the other chickens. I think the other chickens may have started defending themselves, and took out her face feathers in the process. It makes sense to me that if she was coming at them, that's where they'd peck her. So it may be that they worked it out on their own.
They are really enjoying the clutter- and it's fun to watch them climbing around. They actually seem to be playing on it.

They are also really enjoying the protein snacks- so far they actually seem to like tuna the best. So whether those things helped solve the feather pecking or not, I have learned a lot and the chickens quality of life has improved. I am just going to keep an eye on things for now.