Only way I can think of then, would be to use an enumeration in the general object that is related to the specialization and add some logic in the nanoflow
Eg Person is general
InternalUser is specialization of Person
ExternalUser is specialization of Person
Enum_PersonType consists of two values: Internal and External
When you create InternalUser, you set the enum to Internal and for ExternalUser to External. (for directly created Person object, you leave it emtpy)
In the Nanoflow you have the Person object. If the enum is set to Internal, you retrieve the InternalUser with the same id as the Person Object.
does this make sense?