"SAR" hack device won't boot android 11+ GSI

[Maurice1502]

I don't expect anyone to be able to help me but maybe this can be usefull for someone.

My device is a BV9500 (not Pro and not Plus) with MT6763, release with Android 8.1.
Treble Info report it as A-only with VNDK 27

All of Phh-GSI 10/11 and thoses made on top works fine (crdroid/lineageos) expect with this last version of lineageos-18.1 from 21 Jan made by AndyYan (It goes into a "factory reset" loop with a pin set ect ect and when I able to make it work at random time the loop start again)

Anyway my post is not about this issue, I want to talk about a MakeMeSAR.zip that you can find online.

Current Behavior:

With Magisk install and root acces, I'm able to flash this .zip file and it make my phone boot as a SAR device.
I reboot in bootloader and flash system-quack-arm64-ab-gapps.img and my phone boot fine and fast.

I run Treble Info and the app repport now my phone as "A/B" so SAR the app suggest me to use arm64-AB-vndklite.img.

Describe the bug

I try to flash in fastboot system-roar-arm64-ab-vndklite-vanilla.img , it flash fine

But my phone does not boot.... And go into bootloader

To Reproduce

• Run magisk and root
• Flash the .zip
• Reboot in bootloader
• Flash android10 ab image
• Boot
• Reboot in bootloader
• Flash android 11 ab img
• Don't boot

Expected behavior

I don't understand why android 10 boot but not 11
And if you ask why I do this, it's to try to keep my phone update and to be able to use 12/13/14 etc

Smartphone (please complete the following information):

• BV9500 (not Pro and not Plus)
• system-quack-arm64-ab-gapps.img and system-roar-arm64-ab-vndklite-vanilla.img
• Last version of each

Additional context

If someone have any knowledge about this and have any idea, any help is welcommed.