Hi, thanks for the teardown.
But I'm pretty sure that this is just a 1D scanner - it would not support any 2D codes (QR etc). There is most likely just a photodiode inside the whole shielding assembly. According to the datasheet it supports the following:
UPC/EAN/JAN, UPC/EAN w/ Supplementals, UCC/EAN128, Code 128, ISBT 128, Code 39, Trioptic Code 39, Interleaved 2 of 5, Discrete 2 of 5, Code 93, Code 11, Codabar, MSI, RSS variants
None of which are 2D. As such the processing is simpler by orders of magnitude - just process a single 1D analog signal, look for a pattern.