how to prove on a site where I have my area, but am not the root admin of

Currently, per site, only one proof appears to be possible. This leaves out millions of users who command not over an entire site, but just a fraction of a site.
Please add the possibility for multiple proofs per site.

Then for example the supreme court of switzerland could add its web-proof.
https://www.privasphere.com/kanzlei@bger.ch

or many other "SuisseID"-identified lawyers.

I guess this idea is somewhat similar to
https://github.com/keybase/keybase-issues/issues/977
Solutions:
1) It would be great if I not only could specify the site, but also a deep link.
2) I guess the URL to accommodate multiple users per site could also be generically be set - e.g.

example.com/keybase?you@domain.tld or
example.com/keybase?io=ralfhauser (my name at keybase.io)
example.com/keybase?fingerprint=B7BE9E337AA09FA58D3A 97182A20188E87826F38

I probably would even list multiple sites in my proof.

Start by reviewing the issue's proposed deep-link and query-parameter approaches, along with the related keybase-issues#977 discussion. Clarify the requirements for multiple proofs per site and how a proof identifies a subsite or user; done requires an agreed design and implementation scope.

Written by the indexing model from the issue text.