I've only seen two of these in person, both in a LFS display tank. One was owned for about two years, from a 4" juvi up to about 10" when it started destroying all the rock work.
As stated above, they dont target corals but the scrape everything hard trying to harvest algae. This one I saw be so destructive was in "only" a 600g tank.
I would label them as totally not reef safe. Sure, they arent actively trying to kill corals, but in their search for food they will do it. At least that has been my experience.
The other Qouy they had only lived about 3 months in a smaller reef tank, I think it was a standard 210, and died for no reason they could tell.
Cute when small, but they get big and imo totally dont belong in an aquarium unless you're pushing 2000lbs+ of live rock.