We definitely need to solve that usability issue, I definitely experienced it in Grafana.
For Grafana in particular, I know Prometheus driver has a "label name" that is defined in Grafana and can be templatized with metrics labels. It's purely on Grafana side and only works for Grafana.
Having a convention is a quick solution, do we see it used by Metrics internals or only by agents and UIs ? Does it need to support templating with other tags or do we expect the client to be smarter to tags value change ?
I would also suggest displayName (or display_name or else) rather than just name, I think it's clearer that it's for UI and can change.