Any ideas... need to access Entity during configuration, but factories aren't registered until activation

I would like to create database entities and store them in the database as part of the configuration phase of a plugin/module installation. Unfortunately, performFactoryRegistration is not called until the module is actually activated.

I had submitted a suggested patch that did the Entity registration at the end of the module install. Unfortunately, this patch was rejected becuase it violated some key architectural principles.

Does anyone have any ideas about how to create entities as part of the configuration step?

Thanks
Tim