I have 4 kinds of angles fish in a reef tank no problems if you get an angle fish and want to use extra caution feed you fish with a food that contains a product called spong ,I have herd of other people having froblems with certain types of coral nibling fish then switched over to a differnt food source containing a sponge additive and never had a problem again
When the large angels get big and I mean about 10" or more(Not dwarf angels), there is a chance are they will start picking here and there at corals and I have been feeding mine sponge since they were small, so I don't think feeding them sponge is going to dither from bothering corals. Some might be model citizens for a while, however the risk is always and will be there now or later on...