Thanks for the encouragement... But I will never ever try quilting with stretchy furry knits or even flannel-backed satin ever again! The satin slips around and gets 'runs' in it and ravels every time you touch it, and the furry knits stretch out, but you can't stay-stitch them because of the teeny seam allowance. Even the flannel border and backing material were flexible.
My next project is going to be a nice traditional cotton and I will quilt it instead of tying.