Custom port chinese to globalized

Nov 7, 2014
These days I have a Oneplus 7 pro and managed to find a port of chinese MIUI 11 with fingerprint and alert slider working. Issue is, it's chinese so not the best integration for my uses. I am wondering if there is any resources that could help me get a version working from the port I have now? There are a few other MIUI roms for my OP7P but they are all missing inscreen fingerprint and alert slider so quite unusable for my needs. I am guessing the magic happens in the vendor.img but I can't find any recent resources for how to port a rom.

Any advice would be appreciated and I know, if I want miui I should get a xiaomi phone but mi9/9tpro are all but vanished in my country and if importing I would prefer a battle angel edition but they are quite rare so trying to do with what I got for now. The newer phones are just too big for me (even the OP7P is way too big but it was free).