Even the normal AI image generation process often involves some trial and error. Generating a bunch of variants by changing random seed or slightly tweaking prompt keywords and choosing a result which looks the best. Doing multiple attempts with multiple different inputs doesn't seem more crazy than doing multiple attempts with same input and hoping for better results.
If you have 20 letters in your URL, and you give the model each of 2^20 different ways to capitalise them, isn't that pretty close to brute-forcing?
edit: It would also be beneficial to have a script which automatically distorts the image in various ways and checks to see if it would be recognized by a QR code scanner, and give a score so you can see how likely it would be to be scannable in various conditions.