Gregory's Server
Yes, exactly this.
Maybe this is a good starter:
https://socialhub.activitypub.rocks/t/2021-05-01-fediverse-interest-group-meeting/1649/24
as said: Just add any ideas there.
It was also a session at the conference
https://socialhub.activitypub.rocks/t/discovery-for-interoperability/992
Apart from this, nodeinfo might be loosely related
https://git.activitypub.dev/ActivityPubDev/Fediverse-Enhancement-Proposals/src/branch/main/feps/fep-f1d5.md
and related would be @grishka 's
https://git.activitypub.dev/ActivityPubDev/Fediverse-Enhancement-Proposals/src/branch/main/feps/fep-400e.md