This is my take, I don't have a coral beauty, but I have a flagfin and a bicolor (and had a flame), all dwarf angels with the same with caution warning. I had all 3 in my 240 and had very limited nipping, usually when I first put something in the tank the flagfin would take few test nips. I have not noticed any normal nipping. In my tank I have zoas, shrooms, octos, frogs, hammers. I noticed that if I forget to feed them sometimes I'll see the corals pulled back when I get home the next night and suspect they may be a fall back source. I feed heavy to keep down aggression, so that may help. The only one I ever saw nip was the flag, the flame and the bi-color never.