Interesting. Possibly useful to some. I have also discovered that the simplest, most privacy-friendly way to update location is just to do it manually when you change location.

I have a simple script that does this by querying OpenStreetMap's Nominatim server with the city name. It feeds the resulting coordinates thru a Python library that deduces the timezone, and sets the system time to this.

EDIT: I'm so happy.

Ah, ok, got a little confused... GeoClue TZ is an improvement on GeoClue

I didn't even know this was a thing, I just dealt with this manually - now feeling a little silly.