A:Answer There is definitely a M.2 slot as shown in the pics. It is also M keyed, which is good.
The unanswered questions are:
1) Does it work with the current bios?
2. Is it Sata or NVMe 3 x2 or NVMe 3 x4?
Sad thing is that ASUS support doesn't know it's there or if it's supported.
I have seen M keyed M.2 slots that only support Sata in Dell laptops, but the best NVMe 3 x4 also uses M keyed, so that question still remains unanswered.
The current bios (307) doesn't give any clues either. I may just have to buy & try the various types to see which works if any.