Not shure anyone is interessted in this (or just the official stuff?), but i would like to share my expirience here.

Short: I'm running Android 10 with Security Patch from July 2020 on my BV9700.

Long:

I tried with GSI/Treble-images. Almost everything works. Yet found bugs and stuff:

- The bluefilter-screen (for the evening) had kind of flickering to give more or less blue (=make the screen more or less orange). Everything remained readable and it's gone somehow since some days now
- Revolut (Playstore-not-compatible) and Postfinance (Crash cause custom-rom and security-reasons) don't work
- The camera-app is way simpler, doesn't allow the funny stuff like the stock-rom-cam. Same for Blackviews Toolbox - i guess, my airquality-sensor is useless now, but i don't care - better no malicious apps and newest security-patch
- For install the GSI, you need to unlock your phone. This sets a hint on every boot ("Orange state" = No more warranty) and delays the boot for 5 seconds.

WHATEVER YOU DO ON YOUR PHONE IS IN YOUR RESPONSIBILITY - I DONT GIVE A WARRANTY OF ANY KIND!

Edit: If you install this, you need to factory-reset your phone, so make a backup of your data!

My tutorial was this page: https://www.getdroidtips.com/aosp-andro ... v9700-pro/

To unlock the device i used this one: https://www.getdroidtips.com/unlock-boo ... ek-device/ . I used "3rd Method" almost like written.
But after "fastboot oem unlock" (Step 14), you need to confirm and agree on the phone itself by press Volume up. Also, for Linux you don't need all the driver-stuff of course.

The direct link to the Images is this one: https://github.com/phhusson/treble_expe ... s/releases

I've used the file system-quack-arm64-ab-gapps.img.xz. Unzip it and flash it via fastboot (like in the tutorial-link, the first one). The rom is rooted. If you wanna unroot, the developer managed this easily - go to Settings -> Phh Trebe Settings -> Misc features -> Securize

Good luck!

If there are questions in general, just ask.