Syncing gmane group read state across multiple gnusen

Right now I have three different Gnus clients that read the same IMAP
mailboxes, different non-gmane newsreaders and groups, and finally an
overlapping set of gmane groups.

What I would like to do is to synchronize the read state for the gmane
groups that are read on all gnus installations.

Does anyone else have a similar use case?  Does anyone have a solution?

The matches that google has found me is complete synchronization of
multiple Gnusen, but that's not what I found.  And the solutons I've
seen has been sort of hacky.

I guess I'm looking for an explicit export and import of gmane group
article read state...  A bit of automation around that would be
nice, but not essential.  It will in any case be easier than wading
through the articles once more.