with 6.9 my phone freezes - i can't wake phone (must remove battery)
with 7.1A battery drain is about 4-6mA, phone wakes perfect but wifi not working, pops up an error when switching.
i use American Android SD version.
I don't think the kernel is compatible with AOSP roms. Try fikret or rafpigna.
This Kernel works very well on AmeriCanAndroid SD
The last good for me 6.9 build.
You right with 7.1 and. 7.1A wifi not working.
Start from scratch.
This kernel is the smoothest and fastest kernel i know.
This kernel is also the most supported one.
Cheers