Deja vu.
The answers you are looking for have been posted probably 20 times already...
I'm kind of getting sick of repeating myself, so I guess a sticky would be in order.
First, you have to structure the interaction. This is your time to get handled. This is the time to eat. This is play time with me. This is the time we go back to our cage and you have to entertain yourself...
These are toys. There are preening toys, forraging toys, shredding toys, toys we swing on, and toys we chew on. Sit them down on your lap and introduce them to toys, then hang them up in the cage. When they go back, they now know what to do, because they played with them on your lap.
Most pluckers are created.
You hold them too much, and entertain them too much, then when you set them down they don't know what to do. So they scream. Then, when that doesn't work, they get bored. So they preen. And when that is done? Eat, preen, sleep. I'm not sleepy. My tummy is full. I'm bored. I think I'll preen some more.
Never liked those feathers anyway...
Scream n plucks are created... The wild birds don't do this stuff...
Structure the interaction, and teach them to play, and you will have a healthy well adjusted companion bird.
Even relatively easy RB2's can be taught to pluck if they aren't given structure and boundaries.
It really is that simple. Socialization and structured interaction, and a healthy diet.