From my experience, the problem is the lamination of the NZ ones, causing refraction and making it hard to scan. I find that even at the right distance I have to move my phone left and right until the light isn't reflecting
The QLD ones suffer the same issue. I imagine not as bad. But anecdotally the plain paper codes scan as fast as you want. The laminated ones you have to move the camera about to make sure there is no glare interfering with the image