Redeeming Mexico gamepass in USA

All,

My 3 years of ultimate finally expired - time to re-up! I understand that the current cheapest method is to purchase 3 years of CORE, then buy 1 month of ultimate and it will all convert at 1 month ultimate for every 2 months of core, giving 18 months of ultimate afterwards.

Looking at key pricing, it looks like mexico is currently cheapest for 12 months, at around $30. So $90 for 3 years..

so - does the trick still work where i just VPN on my phone to mexico, redeem core on the website, and then switch back to USA and buy the 1 month ultimate?