Thanks Jonny,
The flame angelfish cause no more damage than my other angelfish. However, I would advise against any kind of angelfish if you're keeping fleshy LPS like acans, acanthrophilia, brains, blasto, dendro, etc. If you want those LPS to thrive, don't put any angelfish period.
The angelfish might not peck at it at first, but if there's something wrong with the LPS and cause the flesh to recede or damaged, the angelfish will peck at it and that will be the end of it.
To me, the whole point of keeping a large tank was for the angelfish. I can live without those LPS and keep the LPS that I can. Stuff like hammer, torch, frogspawn, they don't go after.