For those people who might want a bit more confidence when mounting a stack that uses M2 screws, but has M3 mounting holes. Sure you could just mount it using the M2 hardware, but if you need to make sure it's good and secure, here's your solution. Fits M3 holes in 3mm carbon.
These aren't exactly precision made, so you might need to open up the hole juuuuuuust a touch for a perfect fit. But once they are in, they do exactly what you'd expect.