I shared my quick take in another comment tree, but I reread and understand the semantics a little better now, and I like it less, especially the notion that an instance of an object might transform when crossing Namespace boundaries. I get that it is similar to refinements in some ways, but this feels like it would be even more surprising, and I can foresee some gnarly bugs coming from this unless it is trivially easy to visualize the changes to an object between namespaces.

I'm updating my opinion from "mixed feelings" to "against" on this.