Author here, thanks for posting this and glad people enjoyed reading. I did some editing and added a conclusion that boring QR codes are a better choice for real world use. Easier for users to understand and more reliable. These artistic designs are mostly just for fun.

One part which I barely touched was how to mathematically "force" pixels in the error correction section. It's an extension of the ideas covered in https://research.swtch.com/qart but unfortunately I don't grasp it well enough to explain properly.