Many projects define some abstract base class for all entities. Often this base class has at least "id" and "version" persistent attributes defined, and contains @MappedSuperClass annotation. When most/all of the entities derive from such a mapped super class, the ER diagram gets cluttered quickly, because of all the derived->base edges. It would be very convenient if there was a toggle button to "materialize" properties from a @MappedSuperClass to the derived classes (in the ER diagram, not in code of course). So, in above example...when the toggle was enabled, the "id" and "version" properties would simply be listed on all the nodes of the derived classes, and the "red" arrows linking derived->base classes would no longer be drawn. Perhaps the "property" icon for such "materialized" properties from a @MappedSuperClass could get an icon decoration: a red "up" arrow on top of the green round "p" icon.