Get registry for lineage in manifest

I have lineage.registry installed

From my views, I can get the settings from the (lineage) registry like this:

manifest_base =api.portal.get_registry_record('manifest_base', interface=IBokSettings)

Now, I want to get the setting from manifest.cfg in my theme, but all my attempts end up getting
the (main) sites registry record (not the lineage).

Any suggestions?