I haven't taken him to a vet yet. I know what triggers it, as he only does this when I'm on the computer for too long. I mostly work from home, and if I'm on the computer for longer than a 2 hour span, he does it. He doesn't do it if I leave my home, he's fine by himself. It's just when I'm on the computer and can't pay attention to him. Even if I let him on my shoulder, or he's on my arm chewing on a toy, he'll go to his tail while I'm on the computer.
I've tried not reinforcing it. I've also been locking him in his cage when I'm on the computer so he's surrounded by toys. That buys me more time before he'll start, but it doesn't completely stop it. Unfortunately now that the tips have been bitten off the tail feathers fray easily, even when he's not messing with them. I'm just hoping he'll molt those soon.
Oh, and his two longest tail feathers have grown in completely, longer than the old ones. I like the idea of getting his tail feather tattooed, I'd probably do it on my forearm.