sandfish786, my understanding is that you have not found yet a solution until now, right?
'cause I've spent my free time in the past week trying to follow other suggested paths, like trying to dump the /../Android/data/obb folder and descendants. Except that, on Android 14 at least, that trick doesn't work at all (anymore?) Using Total Commander to access any obb subfolder redirects you to use My Files (I am on a Samsung), and My Files only shows 5-6 subdirs from a total of over 40. SyncThing can not even put its nose in the Android folder, I could go on and on but you get the picture.
I've also done an inventory of the apps installed after 10+ years of Android usage, and 50% of them at least would loose their associated data, as they do not provide any mean to export/import it.
The above, for me, signifies unfortunately the end of the road for my trip with GrapheneOS, at least for now. It's a real pity because I had high hopes on it. I understand there are different use cases where what is an issue for me, it's not an issue at all for others. But, as I've already written, with the passing of the years I've slightly changed my view on what constitutes a viable, usable, secure and privacy concerned device. Usability has to be really taken into account together with (and not in contrast to) security and privacy. Failing that, and unfortunately IMHO GOS fails on this point, one ends up with a nifty piece of IT engineering, great for Snowden and other freaks, but not really ready even for tech inclined people (and without going further on details, trust me when I say I am not exactly a rookie).
I'll wait some more time to read eventual replies, after which I will reluctantly revert my shiny (but unused) Pixel 8 to Google OS. It's sad, but I want to use my new device.
Thank you for your time.