I bred some frizzles x Pekins and I got 2 frizzles from the clutch and that's how their feathers started out at that age some frizzles frizzle early some can take awhile to frizzle out from what I've been told but my experience they started as soon as the first feathers started coming through...
I had eggs in the fridge longest 2 weeks and then my pekin went broadie so took them out and marked them and put them under her so far 95% success still have 4 eggs under her 3 aren't from the fridge also I didn't bring them to room temp just stuck them under her!! Maybe beginners luck or...
I bought a young silkie chicken from a breeder who vaccinated and it died from Mereks it was the only one that had it and never had a problem with mereks since! Knock on wood!! When I buy chickens I put them in a separate pen for a good 3 months before mixing and any sick chickens are removed...