I just have SPS and anemones. I never have any problem with Flame, Flameback, Fireball or Cherub angels. My SPS and Clams Grown like gang busters. It is true that they take nip here and there, I do rarely see it. This does not cause problem for my SPS. Their courtship and spawn are very interesting to watch.
For each reefer, the degree of tolerance toward orcasiona nip is different. As long as my SPS are healthy and growing, I could not care less. I had some Red Bud in some of my SPS which have since go away without treatment. I think my angles and Leopard wrasses are responsible. Sometime seeing the fish nip at corals my be because they picks parasites off of the corals.
I one angel that I always have problem with, 0/3, is the C. nox. A very beautiful, strikingly graceful fish, always go for my SPS as soon as she is our of the bag.
I never interested in any other dwarf angels so I do not have experiences with them.