The DESTROY problem is easy to get around...
That just moves the problem from keeping DESTROY in sync, with keeping USED in sync :-)
The serialization is a larger problem. I don't like the idea of everyone having to agree on a standard way of doing things to get the benefits of prior work.
I'm not sure I follow this argument?
If you have a complex serialisation problem you'll be writing custom freeze/thaw methods anyway so it's not an issue.
If you're not - and basically want something that has all the attributes in it for you to Dump/freeze/thaw, then a base class would seem the best solution to put a generator for this sort of thing?
... or am I missing the point again... it is late...