I cut/weed QR Codes on the regular for a high end client. It's a second surface storefront suite and they want it to look uniform with the verbiage. We negotiated a size of no smaller than 3x3, which leaves me with 2-3mm "pixels" its totally doable. I work from the outside in, and pick away with an every other pixel mentality. I do question the wear and tear of window washing on such tiny details, but that lies on the shoulders of the client. If your struggling with the weld function, just use a smart fill and create a fresh graphic without the pesky extra lines, I was back and forth with the designer on that detail and that was the only solution we could find, the wireframe version is absolutely unweedable