Is there a way to influence the serialization process with @JsonIdentityInfo so that it inserts the whole object instead of referencing the id?
@Entity
@Json
Like said in the comments and from the links, @JsonIdentityInfo and the Jackson Generators doesn't seem to have an option to enable inserting objects instead of ids.
After more research we finally found this: deserialize Jackson object in JavaScript containing JsonIdentityInfo
This was exactly the scenario we had and we are now using JSOG, which is optimized for bidirectional references and it works like a charm on server and client (AngularJS) side.