The only thing I know of is overriding the ip address, but it only works
for AT 1.xhttps://www.mycompany.com?mboxOverride.browserIp=60.234.0.39
Maybe a VPN connection to a different geo? Thought this was helpful as
well.
https://experienceleaguecommunities.adobe.com/t5/adobe-target-questions/geo-targeting-not-working-and-showing-challenger-to-excluded/qaq-p/170608