I have an older version of the edge-stitching foot for my Viking D1. For that model, you must be able to adjust the needle position. Depending on the fabrics I'm quilting with, the needle position changes from time to time. (i.e. piecing with my hand dyed pima cottons vs. a quilting flannel).
Love the foot, totally recommend it. Glad to know that there's a specific quarter inch model now!