Sorry, I'm long out this market segment. I handed the project I was involved to the production people long time ago. I'd used commercial/for-pay software and hardware that I don't think is relevant anymore.

Two suggestions:

1) look not for "QR code reader" but for "image processing library/toolbox/toolkit".
2) if you use an open-source (or paid for closed-source) then getting the required FEC/payload ratio and S/N ratio is a quite simple modification. Few lines of code at the maximum. In my experience the difficult part is to understand the underlying concepts of forward-error-correction and channel noise and how they are used properly or misused (nefariously or due to lack of understanding).