When creating a new Tenant, list of available doctypes omits those that extend non-core types

With the Multi-Tenant add-on and Tenant Isolation enabled, upon creating a new Tenant, I'm prompted with a list of "Document Types That Can Be Created". This list, however, fails to list Document Types defined in my project that extend other custom types. The only custom doc types I see available to me appear to be those that extend core types such as File or Document, etc.

I am not sure if the issue is limited to the UI (the "Enabled Types" selection list) or an overall inability to set the domain property uitypesconf:allowedTypes to include them.