Personally, i alwys say "no, not reefsafe"... there is always chances that they will be, but to be, 7/10 times they will just end up shredding corals.
Feeding well doesnt necessarily help much, they graze... so inbetween meals they just 'pick pick pick' at the liverock and whatevers on it. I guess the leather corals etc might be ok... but xenia, polyps and zoas etc would probably end up dying in the long run, even if not eaten, being picked at will just make sure they dont open.
Depends how brave you feel, its an expensive fish to have to take apart your tank to get back out if he does eat corals!