This is beyond the current doman model discussion. This is truly MDR level overrides of either domain.xml of ManagedComponent properties at a level above the server
I'm not envision that we create any components at the domain or higher. We only have overrides of properties to components associated with a deployment. The domain or higher model may define which deployments are active, but not any actual deployments.
I assumed the answer was no I belive?
The only way this applies is if the metadata for FooComponent intersects with the metadata in the domain.
The only question I see is whether a given domain.xml setting actually applies to a deployment. As it stands now we would not know until runtime.