The golden rule with the OSGI stuff is Managed Entities CANNOT cross
classloader boundries. However, you can keep mappedsuperclasses in a
different classloader, that's fine.
One thing I can add ... I'm working on an extension to EclipseLink
that will get around this limitation. I hope to have something
available soon, but every time I start working on it, something higher
priority comes up. Stay tuned.