Maybe off topic, but 'just in case'.
If you export 'datagridfield' settings from registry and put them in (your profile's) registry.xml: I dont think it works. I needed to put it in setuphandlers. py
plone.api.portal.set_registry_record( 'My.Addon.interfaces.IMySettings.location_names',
[{'location_name': 'Some group', 'something': 'Something'},
{'etc' : 'etc'}, ])