I do FMQ stitch in the ditch with my DSM. I have just made myself learn to do it because I don't want to turn the quilt. I don't use a ruler because I have not really used mine enough to be comfortable with them. I use a closely matching thread color. The last one I did was my log cabin QOV and I did each "log." Your design is more intricate, of course, but you can do it. You will be an expert at it when you are done.