Currently it is only possible to link the Workspace / Product records to the following record types:
Persona
Competitor
Creative Brief
Strategic Model
Workspace Settings
This limits the ability to create a report that shows how many products/workspaces have many other record types contained within them.
This would be useful for better understanding utilisation, gaps in data, data entry over time or where some products are just dormant and could be removed.
Reporting is possible at some level as there is an object total visible when modifying the workspace hierarchy (attached).