I have a Coral Beauty in my 60g and although I only have a few corals in there currently, I have never seen him show any interest in them. But it is always 50/50. My CB is all over the tank from top to bottom, side to side, a very, very active swimmer and IMO would go crazy in a smaller tank. You might want to look at the Cherub Angel, I have one of them in my 36g. They are the smallest of the dwarf angels and a better fit (I think) for smaller tanks. Even at that the Cherub is still a very active fish.