Passing "Google Play Integrity Checks" with Keybox.xml Method (Non-Root)

Is your feature request related to a problem? Please describe.

The current microG-version doesn't pass the "Google Play Integrity Checks" in total. Just the "basic" check is passed, the "device" and the "strong" checks fail although the developers put a lot of effort into a solution (thanks a lot again!!!) - see issue "Implementation of Play Integrity API #2611"
Due to this some, for me important, apps relying on those checks will refused to start or work correctly.

Describe the solution you'd like

After a long search in the internet I found ONE solution passing the "Google PLay Integrity Checks" for non-rooted devices. But I can't use this solution because I found no way to import the keybox.xml and therefore I think the Keybox import functionality is not implemented.
So I'd like the keybox import functionality to be implemented as described in the link above.

Describe alternatives you've considered

none

Additional context

I'm running iodèOS 6.6 (the inofficial version, planning to upgrade to the official version 7.0) on a Google Pixel 9 Pro.

Start by reviewing the referenced issue “Implementation of Play Integrity API #2611” and the linked keybox.xml guide to understand the requested import behavior. Define the supported import flow and the conditions for considering the work complete, including whether the device and strong integrity checks pass on the stated non-root setup.