In the picture with all the salt creep on the glass, it appears the only SPS are Monti species. It has been my experience that these gobies are more fond of Acros & clones (branching types). I've also seen them sit on and in branching or tree like soft corals like sinularia & relatives. I think that mostly, clown gobies cause damage to corals when they are spawning, they clean off an area to deposit eggs which would include removing the tissue and polyps from the coral they are hiding in.