Add PO Line from Catalog for Shared Service BPA in local BU

Summary:

Hi all,

we're implementing a global SSO which will create BPAs, some with local PO processing. In addition to publishing those for requesters in the client orgs, which works, we would like client/local buyers to get access to the BPAs using the "Add from Catalog" feature on the PO. This works fine for local BPAs, but for global I cannot figure out how to create catalog and "Procurement - type " content zone access for a buyer in a local BU to get access to the global BPAs. (where the local buyer is not defined as a buyer)

Is this setup supported? Or should I ask Self-service?