Deserialization of core classes migrated from identity to value classes should be using reliable and simple constructors.
The initial prototype relied on primitive Unsafe larval buffering functions to create value objects.
The migrated classes are concrete with existing constructors or static factory methods and no inherited fields.

To support round trip serialization and deserialization of core migrated classes and implementation specific mechanism is needed during the preview period.
A more comprehensive marshaling framework is a work in progress.