And whilst it works for the Mix 3 it breaks the proximity sensor. This modified version restores the functionality of the proximity sensors.
I also added 3 variants, each makes the earpiece louder and louder. Use the loudness 2 and 3 at your own risk. Loudness 3 increases the overall max volume of the device by about 25% in my testing.
Note: MIUI only. Whilst it works on AOSP based roms it breaks bluetooth audio.
Loudness 2 & 3 fixed, should now actually be louder