I've done sashiko on the embroidery machine. Watched what it did. I can duplicate simple lines and curves with a regular machine and the bean (triple straight) stitch. I've done it on quilted sweatshirts. (Not premade sweats and converted) It was mostly border continuous stitching from a stencil. I used poly embroidery thread and some metallic.
You can put together straight line quilting designs very effectively for a block.
I had a couple of quilt people ask how I did it when I wear the shirt.