@Coffee77  From the docs, I thought it was 1 metastore per region and 1 Unity Catalog mapped to that:https://learn.microsoft.com/en-us/azure/databricks/data-governance/unity-catalog/best-practices#meta... 

You then have as many workspaces as needed within that region. Each workspace contains the 3-level namespace, catalog->schema->table. You can have as many catalogs (top level-name space) as you require. You can host your bronze silver gold within a single workspace, i.e. workspace called "dev".  Perhaps you guys already know about this region constraint?

I think Unity Catalog abstracts the storage part away from us. Essentially, it sits on top of a single ADLS2, as you mention. Databricks nicely handles the storage under-the-hood for us i.e containers.

I think the time you'd need to consider additional ADLS in when we exceed things like this:

https://learn.microsoft.com/en-us/azure/databricks/data-governance/unity-catalog/best-practices#mana... 

That is a really interesting point and one I wouldn't have considered without you raising it. I do fear it's easy to overcomplicate a design, though. Thanks for bringing this type of thing to my attention @Coffee77 

I must say, I'm pleasantly surprised to find these finer details in the documentation provided by Databricks.

All the best,
BS