Just to inform that the Xiaomi Mi Mix3 5G (Qualcomm, compatible n78 band) is supported by scat, with the following process:

• unlock phone with the official xiaomi feature in the development options, wait 7 days for the unlock to be authorized after initial registration
• TWRP (andromeda) + Magisk root
• adb shell, su, setprop sys.usb.config diag,adb
• python3 scat.py -t "qc" -u -a XXX:XXX -H 127.0.0.1 -i "0" so interface 0 seems the relevant one.