I'll post this once again as I can't find where I originally put it so bear with me.
All fish are different, just like us. They all have a personality and wll do different things in different enviroments. To say any fish is reef safe, is a bit of a misnomer I beleive. Some do great in a reef enviroment, some don't. Even of teh same speices.
On thing I've noticed though over the years is that fish can somewhat be taught if you will, a new behaovor. They are smart.
I've kept several fish in my tanks that others have had nothing but bad luck with. Why are mine different? I don't know. But I can give you this advice. I feed my fish, just about every day. They are accustomed, or "trained" to get their food from me. So because of that, they don't go "looking" for other foods to eat. They look for ME to feed them.
Here's another thing about the "conditioning". I bought a large FOWLR setup from a guy, fish and all. He had the system for over 3 years. Some of the fish are large tangs that came with the system. All he ever fed the fish were sinking pellets and sheets of Nori.
Whe I got them, I tried to feed them frozen cubes of Brine and other foods. If I just dropped the cube in the tank, they ignored it because it floated on the waters surface. If I thawed it out and poured it in where the food sank, they would devour it. If I put a sheet of Nori in the tank, floating on the surface, they would devour it however. Why? Becaus ethats what they had been "conditioned" to eat, sinking food or floating sheets of nori, nothing else.
I have been slowly converting the tank over to a reef. I removed the rock that came with the tank and added real coral LR. It has some alage growth on it and yet the tangs and even the rabbit fish don't touch it. Why? My guess is because it's been so long since they saw any, they are now conditioned not to eat it.
Sorry for the long post and you may disagree with me but these are MY observations on MY tanks for the last 7 years. Good luck.