Welcome!!!
I have a plucker on my hands too, Have You taken him to the vet yet at all? Occasionally there can be an underlying cause. My Brown headed has a skin infection that was causing her to itch, and once we took care of it, she slowed down a lot.
I know some birds will pluck if they have dyes in the food, and I do know that the fruit blend has dyes because I gave that to Luna also and switched her to a natural pellet.
Sometimes things can trigger it, and only you or a behaviorist can figure that out.
But a vet is a great place to start, that rules out illness. Then from there you can try other things if it's a behavior issues.
Good Luck, even though the skin infection is gone Luna still plucks sometimes, it's a lifelong uphill battle