It will most likely never be possible with the official rom for the international version as there are physical hardware differences since the 5g model has a different modem than the international version unlike previous oneplus phones like the 6t where the only difference was software. So no way to convert to international and receive official updates from oneplus. But you can run other custom roms though i havent found any that seem to work with 5g as i have to change my network type if i want mobile data to connect right at all.
Nope. You have to get the bootloader unlock token from OnePlus before you can do anything. It's the dumbest thing I've ever heard of. LOL. I learned my lesson to never buy carrier phones. Miss the good ol days. Ok, venting done. So yeah, you have to submit for a token after getting your SIM unlocked here...https://www.oneplus.com/unlock_token. Oh, and it will take at least 7 days! LMAO.