How can I back up app data from an unrooted phone?

I’m trying to get normally‐inaccessible app data off my ageing Pixel 3 running Android 12. It’s OEM‐locked so unfortunately I can’t root it without losing the very data I want to try to back up. I don’t really care about being able to restore it to another Android phone; I just want to get whatever data off the phone I can. Things I already know won’t work: * adb pull: requires root to access app data * adb backup: deprecated and seems to have been completely neutered for Play Store apps by now * Google cloud sync: not an option for many things (e.g. comprehensive Chrome history, Element’s database) The tentative plan I’ve hatched is as follows: 1. Obtain a burner Android phone 2. OEM‐unlock the burner phone so as to be able to flash something that will let me extract data from it (e.g. TWRP, or whatever people use to root devices these days) 3. Perform a device migration (“D2D transfer”) from my Pixel to the burner phone – I know this won’t necessarily recover *everything*, as apps can opt out and there’s potential encryption issues, but it seems to be the most comprehensive app backup option available (hence e.g. Seedvault [pretending to do D2D transfer](https://github.com/seedvault-app/seedvault/issues/165) to achieve more complete backups) 4. Exfiltrate the data from the burner phone in whatever manner The question is, will this work? I can imagine various potential issues, but it’s difficult to find information about online; maybe there’s some Play Integrity/SafetyNet type thing going on to ensure that migration doesn’t happen to an unlocked device – I’d assume there’s *something* to try and make it harder to subvert Android’s app security model with this? If it won’t work, is there anything at all that might achieve similar results? (The Android developer documentation has information about [testing D2D backup directly](https://developer.android.com/guide/topics/data/testingbackup) , but it doesn’t give the impression that you can access the resulting data.) If it will work, is there any way it could be simplified (e.g. emulating an Android device in a VM on a computer and using USB passthrough of some kind for the migration, to skip the need for a second phone)?