Look at the methionine level in the feed- some organic feeds do not have as much as they should. 20% protein should be good but eggs and yogurt actually do not have that much protein in it. It is easy to throw nutrition off--for two weeks, give them nothing but the game bird feed.
If the feather picking is still going on after two weeks, send in a manure sample for a float test. It really does sound like they had a rough time.
I have read that slufa drugs can be hard on birds.
Well I searched methionine sources and eggs, fish, meat, sesame seeds, Brazil nuts and some other food sources have methionine in them. As for methionine levels in the feeds or pellets at the feed store there was nothing higher than 0.40% and we have the starter that already has the highest amount from them. Our electrolyte vitamin pack only has 0.10% methionine. Guess I'll continue the boiled eggs, mealworms, yogurt, and supplements now and maybe cook up some turkey also for these young'uns for protein + methionine content. All the feather-picking research I've done is frustrating because there is no product or solution that seems to be effective short of isolating a bird or sending it to freezer camp and for other chickeneers it seems to be a seasonal thing. Some chickens are toe pickers like mine, others have roos that get chewed by the hens, others say new quills tempt chickens to pick on other chickens, with some it could be a nutritional deficiency, others it's a habit, etc. My Silkies are loaded with feathers from the top of their crested fluffy heads down to their feathered legs and toes and never had a feather-picker in the bunch. The Leghorn we once caught yanking out their crests and beards was instantly rehomed to a layer flock.
I'm beginning to think our Breda's reason for picking at herself is not just boredom but high-strung personality. At the vet's office where there were 3 of us humans in the exam room she tried to look nonchalant and groom her feathers as if unconcerned. When the vet office cat looked into her crate she started the grooming thing again. She just may be a high-strung breed that turns to herself (and feathers) for comfort and toe feathers are easily reached - don't know - just guessing here but after watching her for a couple weeks we noticed she turns to grooming when she startles from noises, or sees something flapping in the breeze, or humans she doesn't know appear around her, etc. Our sweet APA Ameracaunas happen to be kooky spooky jittery alert personalities but they don't turn to themselves or others to pick at feathers.

