... adding SessionBeans and Skipping ConversationBeans

What do you mean by ConversationBeans? SessionBean is an internal representation of an EJB session bean (i.e. a bean provided by an application). AbstractBuiltInBean is a base for most built-in beans (beans provided by the container, e.g. a bean for javax.enterprise.inject.Instance) which are handled in a special way. And to be honest, I don't remember the exact details