If you just want something public, posting to the existing categories (implementation / protocol design) and using the lightning tag should be fine? My impression is the fedora folks found it better to go with general categories and more specific tags on their discourse, so I think that approach should be workable? Ref: Navigating Fedora Discussion — Tags, Categories, and Concepts - Fedora Discussion
If you want a more specific workgroup I can set that up too; but need to know who should be members, if it should be private, public, or read-only public.