Serialization via Data::Dumper or Storable seems to be the Achilles Heel of all of the inside-out implementations. ... And, of course, fixing that would require making it possible to break encapsulation via manipulation of the serialized instance - thus defeating the raison d'être of inside-out objects.

Not any more. Object::InsideOut now supports serialization using Storable, and it does so without breaking encapsulation.