With latest system update (QF3 for my G9350), error 'conflicts with an existing package by the same name' when install S8 AOD apk (from apkmirror above) is gone now. :)
No quicksetting for GPS, but the location setting is searchable in settings.
You need to request on miui site with your mi account. Follow the guide there to unlock the bootloader after your account is approved.
It works fine on 5.11.19 dev version.
I have the same error on my phone with 25 version flashed via recovery (not fastboot zip).
I extracted the system.img from stock cm-11.0-XNPH25R-bacon-signed-fastboot.zip and fastboot flash system system.img, afer that flashing the ota zip was ...