The (F)DFE API supports an URL parameter called “ipCountryOverride”. It can be enabled in a “secret” developer dialog. I always suspected that this is somehow used by Google engineers when they need to bypass geo blocking, but I could never figure out what to pass as a value. Booleans as well as locales don’t work and obviously, you cannot use an IP address to represent a country. What’s even more curious is that dialog loads data from a CSV file (which, of course, isn’t publicly available)!

You connect to a host called android.clients.google.com, when talking to the Playstore. That’s actually a DNS CNAME and can resolve to a number of different IP addresses. The Playstore is not a single/central server system! Google likely runs a separate instance of it in a local datacenter in every country in the world.

So, maybe the value for the ipCountryOvveride parameter is the IP address of the (country) instance behind the load balancer then?