feature requests

What is the best way to request for some features, pop them up in here for debate, or create an “issue” in the issues tracker ?

Either (or both) is fine. The issue tracker has a triage:feature label available to classify feature requests, and issues integrate nicely with commits and merge requests in GitLab. OTOH discourse may get a broader audience.

how do I set that triage::feature label ? I don’t seem to find how ?

It needs elevated privileges. Ping a developer and one of us can classify it.