Display logical many-to-many relationships (diamond) on Descriptions view

Issue:

When viewing the Descriptions view the many-to-many relationship tables that are represented by a diamond in the Logical view assume the standard entity/table display. This switch can be context jarring and gives an implied physical relationship when we're still representing a logical model. 

Possible solution:

A preference could be added so that entities with the the many-to-many view selected can be displayed as diamonds in the Descriptions view.