Possible to separate globality from validation's top-level element choice?

Hi,

I'm new to the list so pardon me if the above has been a
discussed topic.

Are there plans to separate the globality of an element
from its current automatic candidacy as a choice to be
validated as a data instance top-level element?

Just as an example, perhaps the introduction of something
like <xsd:validate name="TopDoc"/> to explicitly declare
that "TopDoc" is the one and only permissible top-level
document name of its defining schema would help very much
to separate the element's degree of referenceability from
being valid or invalid in a data instance.

There appears to be increasing practical needs to have
this distinction than a mere nice-to-have.

Please see if you could consider, or point me to any
area that has concluded this if there were previous
discussions.

Thanks.

cheers,
mc