For those who are curious, these are 2DID Datamatrix codes, also used in the semiconductor industry extensively to mark wafers and chips. If you pick up an Intel CPU, its going to have a couple of tiny datamatrix codes: https://en.wikipedia.org/wiki/Data_Matrix
https://www.laserax.com/blog/data-matrix-vs-qr-codes
Looks like Data Matrix has higher error correction (per size) and better data density (at every size). QR Code has a higher theoretical storage capacity, larger maximum size, and multi-byte data support (rather than limited to alphanumeric), none of which applies to this use case though. It also looks like that Data Matrix may work with a lower contrast than QR Code. Both can be read from any angle.
Honestly, purely from a technical standpoint, the biggest arguments for QR Codes is their popularity/adoption, and things like that you can stylize the code itself.
Maybe I need to do more research, but on the face of it Data Matrix looks like it is technically superior.