Hello! I got to thinking... OP has said they only have one variant of the OPO. That means they all have the same radio. If you flash the radio with the firmware from a US variant, will you get LTE band 17 and 4?
XDA Developers was founded by developers, for developers. It is now a valuable resource for people who want to make the most of their mobile devices, from customizing the look and feel to adding new functionality. Are you a developer?