I have zoos, lps, and mostly softies in my tank (no sps or a duncan) and my CBB leaves those corals alone. My CBB eats PE mysis (very well) feather dusters and his favorite is colourful clams
I had a small sps frag for a short time (sps never does well in my tank, they just bleach out) and while I had it my CBB left it alone.