i have flashed this modem on my Mi6X, the change in reception is incredible. i'm not concerned about the batterylife part of things because i get a full day of use without problem.
I also had a problem with the antirollback when flashing the modem.img but this is easily solved with flashing the dummy.img first to bypass the antirollback feature. and then flashing the modem using the provided steps by
[U]n0f3ar[/U]
https://en.miui.com/thread-3436592-1-1.html
using this method is all at your own risk ofcourse.
n0f3ar keep up the good work!!