Well, according to the PDF diagram of the mainboard.
The SSD screw standoff is:
16 SSD Standoff ES00000O100 STANDOFF 1.4H 5.0D 0.8H 1.0D M1.4 A
So, it looks like one needs a M1.4 screw.
The D is diameter, so I think the screw hole is 1.0D, and the outside diameter of the standoff is is 5.0D.
I don’t know how long the screw thread can be, or how thick the screw head can be.
I think the maximum clearance for the head is 1.2mm, so the 0.8H figure is probably for the screw head.
This just happened to my FW 16. Not a great first impression 
Sorry to hear that I see that you have already contacted our support team, they should help you out with the replacement.
FW opted for replacing the whole mainboard.
I have received and installed it according to the replacement guide.
I now have a running system.
A lot of trouble for a little screw.
Thanks for taking the time to let us know. I’m pleased that you’re up and running.
Dino
I came on here a few weeks ago because we had the same problem and I was very nervous if Framework would make good on this issue. I was nervous because this was my first experience with this company and not sure what to expect. They sent a new main board and we got it installed and all is good now. I can now say I am definitely a Framework fan! They make good and stand behind their products. I will recommend them to anyone that is looking for a new laptop. Of course I do hope they can figure out a way to make the screws better so others don’t continue to have this issue, but at least I know now they will make sure to make it right to those that do. Thank you Framework support team.