It sucks. Lots of NUCs come with a very small capacity Optane drive already installed. Many users want to replace it with a regular SSD. The nasty surprise is that the screw is overtightened. So when they try to unscrew it, a common outcome is to ruin the motherboard.

Some laptop modding anecdotes: Thinkpad X61's mini-PCIe Wi-Fi adapter has the same problem and is well-known among hardware modding users - the screw is tightened and glued in place. When someone tries to unscrew it, one must carefully apply a torque with a high-quality screwdriver, otherwise the consequence is ruining the screw. I made the mistake and killed that screw when I first encountered that screw.

Fortunately there was a simple fix: just use a Dremel tool to cut the screw through the circuit board of the Wi-Fi adapter. The PCB of the Wi-Fi adapter is ruined, but you can now replace it and install a new screw without a problem. (and I think the ground plane is under the screw, just copper without other traces, so the original card may even be fully working, but if you've spent so much trouble to remove it for your upgrade, it's definitely not something you'd like to continue using...)

Since then I went to get a set of high-quality screwdrivers and never had the same problem on other similar machines.

They're M2 x 3mm? That's small but not ridiculous.

Place a magnet on the screwdriver blade.

I find it a bit odd how most motherboards seem to use M2 screws, but most of the add-in card M.2 adapters I've dealt with use M3 screws, and the M.2 spec only talks about M3 screws.

In the end the size of the screw doesn't matter as long as it fits in the hole. Your M.2 isn't going to just pop out because the screw is half a millimeter smaller in radius!

Half a Millimeter is huge! Just finished replacing a part of my truck that required a 5.5mm socket. I had a 5mm, 6mm, 1/4, and 3/16, none of them worked.

The M.2 slot requires downward pressure.

on most motherboards you could probably leave the screw off and it would be fine forever. not that I've done that. yet.

The connector requires a small amount of downward force to slot the nvme device. Without a screw, the device can easily pop out of the slot.

If only engineers working on that sort of product had some kind of way of using a plastic tab or something to hold things into place. Like have lunch with the memory socket or PCIe people and talk shop.

I was shopping for an Apple 2013 SSD to PCIe or SATA converter yesterday, and I've found that some adapters have a configurable clip on the PCB instead of a screw. You insert the clip on the PCB according to the size of the SSD and viola.

Someone buy that engineer a beer.