The 16 inch blocks are stabilized so you could stitch anything you wanted inside. If you outline the stars the only drawback I can see is the many turns you will need to do to sew around the stars. I would put in a little basting inside the blocks if you decide to outline stitch the stars with your walking foot or you might get some shifting as you handle it. I just finished a star quilt with sashing that I FMQed. Have you ever tried to FMQ straight lines? I didn't do too badly but it was easier in my opinion then maneuvering the quilt around to use my walking foot.