Multisite Marketpress questions

We are exploring the possibility of creating a multi-site Etsy style site with multisite Marketpress.

So far we’ve found the information on how to do this to be rather scant. Has anyone actually ever done it?

For now, an initial question.

Following advice, it appears that the New Blog Templates plugin can be used to set up new stores to automatically have the theme, pages, etc that are desired – this can create a consistent aesthetic across the mu network.

However, what if changes are desired to that default look/feel? Changing the template store site does not affect site stores that have already been created. You would have to manually go into every single store it seems.

Has there been any consideration to this sort of problem? Any ideas on how it could be solved?