Im on nabu Global.
Unlocked the bootloader today.
I try to get MIUI 13 early, but there's no TWRP yet and the only MIUI 13 rom is the Stable Beta Recovery from China, which I would be happy with.
But it seems without TWRP or another custom recovery, we can't flash any recovery ROM from other types (stable to beta) or other regions (Global to China), right?
I'm still thinking there may be a way to extract the IMG files from the recovery zip and flash them with fastboot one by one.
Edit:
found the fastboot file
nabu_images_V13.0.3.0.RKXCNXM_20211228.0000.00_11.0_cn_1d92f2dc98.tgz
on
https://mirom.ezbox.idv.tw/en/phone/nabu/
I can say there are now hundrets of MIUI ROM indexing pages but none of them listed the fastboot ROM. They all came after the original ezbox.idv.tw, this is the oldest MIUI ROM indexing page I know of and I have been using it in the MIUI 4 days. I found several ROM links there that weren't available anywhere else.