The Model MBean spec explicitly calls out a set of features that are optional, e.g. persistence, notification logging, attribute caching.  The behaviour when a feature is not present is simply to do nothing.  This makes it difficult for a program to use these features.  It must somehow arrange to observe that the feature is present, e.g. by asking for notification logging, then sending a notification to see whether it is logged.  That's very inconvenient.

This behaviour also means that it is impossible to test these features in a test suite, since it is impossible to distinguish between the feature being unsupported and the feature just not working.

There should be a way to ask the implementation whether it supports a given feature.  Or, the optional features should be made mandatory in the next version.