Metropolitan areas?
I have noticed that Regional Development Commission Boundaries (DPIRD-020) have not yet been added? I wonder if this is a feature that will be added in the future. Or if it is possible to add to this project.
Happy to help if it is possible.
OSM-Boundaries is only a display layer, showing data from OpenStreetMap. We do not add or manipulate data in OpenStreetMap. Your question seems like something that should be directed to that community, or just add the data yourself into the open database, if the license permits it.