Apple New Orleans wrote:
I'm afraid to root the phone because I don't want to write over any more data. Yes, the customer performed a factory reset.
I do not think the Root will cause so much overwriting, but since factory reset is already executed, and there is very high possibility that you would need to unlock bootloader before writing non-certified binaries (I am not 100% sure if it needs unlocking, but I guess it would), I think at this stage recovery is very unlikely.
You will 100% need root to reach internal memory as a whole (unless you can make direct on-board connection to eMMC with device booted), so check if device can root, if not then unlock bootloader and root and secure DD image via ABD shell, but at this stage much data will likely be non-recoverable even after an image is made.
there is a lot more research needed for such situations and from my understanding there is not a great deal of information available regarding specifically recovery from such devices. Most firms who can perform this will often have some internal process they develop for such a case, and I do not believe there is any commercial solution available to you for this.