It is difficult if not impossible for multiple separate instances of a KF OSGi framework to be created with a single JVM due to its reliance on system properties.
It would be much better if instead of using System properties the framework checked a Map first, and then only if a value was not found then checked the system properties. A Framework could then be created with a Dictionary.
The other bundles should use their BundleContext.getProperty() method as they check the Framework properties first and then the System properties.