composite id as part of an other composide id

I did not read this limitation in the manual. "Always" is not there. Also I read the following in composite keys in the manual:

As illustrated in the previous example, you can have association attributes as part of a composite identifier. However, there is one limitation: you can't have lazy-loaded associations as part of the Id. All associations that are part of an Id are loaded in eager mode. In the previous example, although FPatient association was declared with TAssociationProp.Lazy, using a proxy, this settings will be ignored and the TPerson object will be fully loaded when a TAppointment object is loaded from the database.

Can you please explain it a bit more?
The first level is Tapipatproto that has a list of Tapipatprotostep (second level) and each Tapipatprotostep has a list of Tapipatprotosubst (third level).

  • The Tapipatprotostep list of objects inside the Tapipatproto will be loaded in eager mode anyway?
  • On the third level (list of Tapipatprotosubst inside each Tapipatprotostep) it must be Lazy-loaded in order not to happen this problem?

So, Aurelius with composite keys can have one eager and one lazy-loaded level in an entity?