UnifiedOop::dereference uses RawAccess<>::oop_load().

That's unlikely to work for ZGC, as the resulting oop may have bad color bits. This is one of the reasons why the jfr leak profilier doesn't support ZGC.

The API for dereference provided by UnifiedOop probably cannot support Shenandoah at all, since there's no access to the base object for Brooks pointer access.