The Barker view is extremely preliminary and has a number of issues. I have a much more advanced version of this that was an extension of this project and addresses additional ER concepts such as Euler-diagram display of subtypes. The extension works well on small diagrams, but unfortunately is sufficiently slow on larger models that I can't release it until the performance issues are addressed. I'm not talking about a minor slowdown on load, but several hours doing shape and line layout on a model that generates ~50 relational tables.
To be honest, addressing this is not on my list in the next year, but is something I want to get running better once some core pieces are in place. I might try some experiments to see if cutting the feature set back (for example, the new version generates numerous diagram notes for items expressed in ORM that are not directly expressible in ER) brings the layout back to an acceptable level. Theoretically it shouldn't be slower than laying out the relational view.