If you read the old poultry husbandry books written back in the early 1900s, molting patterns were something the farmers documented and culled or bred for. Even within a single breed, some birds just molt long and hard and don't lay a single egg during that time while others continue to lay 1-2 eggs per week through most or all of molt, and then get through the process more quickly.
Molting is definitely something I'm paying more attention to when selecting my breeders now that I'm more aware of how my birds handle a rougher year. My three Australorps and a handful of my NNs handled molt the best. My EEs were the worst, and my Dorkings were pretty hard molters, but also are NOT winter layers. A actually gift my Dorking roosters some other laying girls because they were becoming so frustrated by the Dorking hens.
My worst molters, as in hard, fast and massive feather loss all at one time, get raw lamb at least once per day along with extra veggies, black oil sunflower seeds, and vitamin supplements along with their regular feed to help them get through it. I put them in my isolation pen and treat them until I see them sprout feathers, which usually occurs in about three days, but with so many birds here I can't do that for all of them.
