The only time mine move is from over crowding, something I'm going to be forced to do something about someday.
I have leathers, xenias, mushrooms, zoanthids, 2 frogspawns, polyps, candycane, clove polyps, meat coral, monit cap, and such and I have never seen my BTA's bother anything to the point of death. They simply have walked over them, next to them, even parked on them for a day or two and then moved on to where the water was just right and they tend to stay there.
Least thats been my experince so far.