Changelog is too big for xda, so it's included in download folder.
If you are using Global /China Stable or third party rom (Xiaomi.eu), please download China Developer from here (search for "小米MIX3最新 开发版 线刷Fastboot完整包点击下载") and flash it, then flash PE system.img.
It seems current stable rom has some bugs in vendor or firmware (e.g. Google Camera is laggy).
Please note this rom is not maintained as my daily driver is FlokoROM GSI.
Camera (including 4K video)
Bluetooth (audio, in-call audio)
Dual SIM, Dual 4G standby
Sensors including proximity
Slider (actually it's working, but no app to handle)
OK Google detection in any screen
Bluetooth call for some users/devices
Android Auto (display flickering)
Google Pay should work if you use MagiskHide Props Config, but I can't test since my country (Japan) uses hardware level security (exclusive for Japanese models) for payment via Google Pay.
Currently generating ZIP is broken, so you have to install images one by one.
1. Flash the latest *Official* China Developer ROM (xiaomi.eu rom is not supported)
(If you are using other roms before, please wipe data)
2. Download and flash system.img
3. Download vbmeta.img and flash it with this command:
fastboot --disable-verity --disable-verification flash vbmeta vbmeta.img
4. Flash Magisk
Pixel Experience team and other developers
I'm also building custom kernel for Mi MIX 3.
To enable tap to wake, flash kernel and open display settings.