Are you storing the mapping of place to pubkey anywhere? If so, it might be able to be done with ZKProofs instead, right?
Regardless, this might also be useful for Onosendai’s cyberspace that is mapped to physical space @arkinox
Also, my thinking was less around mapping people to exact places (though it could be that like in your example project).
I was thinking of just using it for simple whitelisting. So you could stop foreign agents from pretending to be citizens online for example.