I love QR code quilts. Here's another idea to use them. I printed small copies of the code to fabric and then cut them up and used it like a normal B&W fabric. You can still read the code depending on how large or small you print. I did an applique Q of the names of the animals our kids have and then used the fabric for their tails, the inside of ears,belly, etc.
'Scuse the lousy quality on the photo. Each block has some, or a lot, of the qr code fabric in it. (The B&W kitty with the purple belly in all qrcode.) I was is a big hurry to get it into a suitcase to get it on an airplane. I wanted to us small copies repeated for a border but ran our of time. Ah well................