I have 3 pluckers - Bella, Sully and Lolly. All 3 came to me as pluckers and had been doing it for some time. All 3 have areas where they cannot grow feathers, not even down. Lolly is completely naked everywhere except her head (duh -- she can't reach that), her tail and her primary feathers on her wings. She plucks her coverts. She also barbers her primaries a bit, along the sides so they will not carry her weight. She launches herself off things occasionally so I think she used to fly. I hope she can someday fly again, but I know she will never be feathered on her body.
I'm not interested in collars or vests or capes or any of that business. If the bird chewed on its skin I might think differently of course.
Both Bella and Sully do much less plucking now than they used to, although Sully plucks a bit around the back of his neck and shoulders during the winter.
I think its common for pluckers to stop for a bit when they first move to a new home. They often start up again. I've heard this from several people. It is a difficult habit to break when they've done it for years, especially if they use it to soothe themselves. A coping mechanism I mean.
My other Eclectus don't appear to notice that the plucker looks different, or if they do, they don't care.
I've not had one bird begin plucking with the introduction of the pluckers to the flock.
I try to bathe them very frequently and that does seem to help. But mostly I accept them for who they are.
Edit to add: Bella discovered pinecones and now keeps herself busy and does very little plucking. Sully only works on feathers seasonally now, and not under his wings or along his sides anymore, where he was very naked.