How to move production data of a postgres based relstorage from a currrent cookieplone based docker swarm live setup to a similar staging site

During Plone Tagung 2025 in Koblenz, @fredvd gave a short talk (not recorded) how to convert Postgres production data to a local ZODB Filestorage database on a dev machine using zodbconvert and a specialised container fired up in parallel to do the job without touching the running production containers. Great thing. We need the link to the docs!

But what we lack is to document the simplest documentation to dump the Postgres data and file it into a staging site.

Yes, I know it is beyond the scope of Plone and should be reachable independent of Plone setups.

But guess what? I simply need these instructions handy and better: Distilled into a make command: make export relstorage dump and make import_relstorage_dump

I am reentering that topic after calming down from the conference stunt.
Help welcome.

Any links to existing docs?

Cheers Armin