Hello Michael,
I just stumbled across https://trac.torproject.org/projects/tor/ticket/32978:
Find a working alternative to using MaxMind's GeoLite2 databases
Since the Tor project teams seems to be actively researching, maybe it is a good idea to get in touch with them more soon. Since I am currently out of spare time, may I ask you to do so?
Thanks, and best regards, Peter Müller