You didn't have to wait the 169h? I managed to create the new US account but have to wait unfortunately.. what exactly did you do?Yes, I had the developer options enabled. It finally worked, but creating a new Mi account through another PC. My mistake was to use only the phone to create it. Thank you anyway
For everyone else, there is no need to use a Google account as the only important step seems to be to create the MI account under US region. After that you can use a phone from another country with its own country code if you need to.