VPN farms and using remote servers are all with a bit of effort detectable. It starts a new arms race but all it takes is to catch the account misplaced once on a change to then keep that history and expose the discrepancy forever. Its going to be quite difficult to get and maintain a genuine domestic IP that is unique per account and doesn't then get shut down often.

Easy, you just ban all known vpn endpoints and cloud hosting provider IP ranges. 4chan figured all this out over a decade ago.