Currently in the ER Modeler, the only indication of any constraints you have on a table is the display of the little key for the PK.

It would be nice if you could also enable display of FKs, indexes, unique indexes and check constraints displaying their name and (configurable) the column names that are a part of that constraint, such as in the attached screenshot.

You should be able to toggle the display of this just as you can toggle the display of the Physical Schema Level, or say Nullable Columns.

Currently, when working on a new model/design, you can't easily see those attributes without clicking table by table on the diagram and looking at the properties or expanding the tree & related folders, which also means you can't print out the diagram for whiteboard type design/code reviews or reference.