Here is the thing.
Few will SEEK OUT corals to eat, but some, like a pencil, really won't care all that much if they are in the way. They plow right through. Others, like the blue tuxedo, are smaller and perhaps more dainty. IMO, all pose SOME threat to corals - particularly soft corals, though it may be a "keep an eye on." Their greater risk is in being bulldozers and collapsing your frags or rocks...and in some tanks, starving.