Scalding helps most with wing and tail feathers and under the wings. . My drum plucked is nice but there are aways a few that end up with broken wings legs and tore up skin. The later in the day and more tired I get the more that happens. Those just get keep for us instead of sold to customer.
Sounds blasphemous, but with so many free birds, I just lop the wings off.
At least I did on the last ones.
My buddys farm does 25,000 chickens at a time. All automated feeding, etc, and one floor so they all run around together. Antibiotic free, etc. 44 day turnaround. These ones are the rejects they don't want. He says sometimes they are a bit too small, sometimes a bit too big, and sometimes the guys just get lazy, cant catch some of them and say heck with it.
I dont know a thing about farming.