DIY Mac Pro data recovery

continued...

Losing the data from this drive will be a complication for me, but fortunately, it's not a catastrophe. The data that is missing is just not so critical that it warrants paying for recovery by Drive Savers. At least I'm not ready at this point.

Drive Savers does provide free estimates, so I would suggest contacting them. They are also recommended by Apple and other OEMs as well. I don't know if they still do this, but years ago they did not charge if data could not be recovered. If anyone can get the data, it is Drive Savers. I'm on their mailing list and once in a while they send a story about a successful recovery from an SSD or phone where everyone thought it was impossible. I have also seen another professional data recovery service mention that they will send drives to Drive Savers when it goes beyond their abilities or resources.

But I might spend for the diagnosis by LMG if there is a more sophisticated way to get the drive to mount for someone with skills and tools to do that.

The tech seems to know more than many do, but I cannot say what his skills are for data recovery. You can tell the tech to try to do a low level block clone of the SSD by using the third party command line utility GNU ddrescue. He can then try whatever he wants on the clone such as any file repair utilities or data recovery apps. Unfortunately if the APFS file system is used, then the only file system repair utility available is Disk Utility First Aid which isn't able to do much.

And if it won't mount, then it's over and I send it back to OWC to test to see if the drive itself failed which would trigger a warranty replacement.

If you are going to return it, then I would attempt to use Disk Utility to erase the SSD in an attempt to protect your personal data. If Disk Utility is unable to erase the SSD, then the tech could try using the command line utility "dd" to erase the SSD....it really doesn't need to write to the whole SSD, but just enough to destroy the partition table as it should trigger all the SSD NAND cells/blocks to be erased. Of course if this does not work, you don't have any other options to destroy the data.