BAs don't take any longer than any other bird to molt. As everyone has said- increased protein seems to speed up the process.
My flock is not actually molting because I have been battling feather pickers all year, but they are finally growing some feathers in since I culled the last two pickers. It is amazing to see how ferocious and grouchy my sweetest hens have become. They are not to be trifled with in their prickly state. My 2 most submissive hens (the ones who were badly damaged by the picking) have been chasing the more dominant hens away from them and giving them a good peck on the ear to boot. They seem to have the attitude "We are so uncomfortable that there is nothing you can do to us to make it any worse! So GO AWAY!" Poor girls. It's nice to see them fighting back for once, though.