I now have a half black, cherub, and coral beauty that are no problem with any corals that I have (SPS, LPS, pipe organs, GSP, and a few zoas). In the past I've had nox, flame, another coral beauty, and flameback that never bothered anything either.
The one that did cause a problem was a lemonpeel. He started nipping polyps 2 minutes after being introduced to the tank. To my surprise, my wife caught it with a net in 10 minutes without tearing down any corals!
I've had a foxface that nipped at the pipe organs and that kept them from opening fully. He "came up missing" one day and the corals recovered just fine.
A couple of months ago I got a Klein's Butterfly hoping it would eat some of the tulip anenomes that I had in one tank. He nipped at the acropora polyps to the point that the polyp extension was very little. I got a big net with frozen brine shimp in it and caught it in about 30 minutes. He's in jail in the sump now waiting for someone else to adopt him.
From what I can gather most of the dwarf angels are OK but a few individuals can cause problems. Also, most of the larger angels will nip corals while a few individuals will leave them alone.
Good Luck!