I've not found conclusive answers around DX and deploying/retrieving custom settings in a sandbox or production org.
I did see this: DX Orgs and Custom Settings
But that post is over a year old at this point. Haven't seen anything in the DX release notes about custom settings.
Is this still not possible to deploy or retrieve via the CLI? Is this technically possible otherwise via SOAP? If anyone can share a developer doc illustrating possibilities it would be sincerely appreciated.