We would love to update Vietnam. But to update it we need the data to exist in Openstreetmap. As it is today, there are no such administrative borders created there.
This site is useful to browser OSMs borders, https://wambachers-osm.website/boundaries/ . Their level 4 fits our "county" polygons, but we would need a level that's matching those 8 regions to be able to import the data.