Ok now what I am going to suggest may sound like it might be hard, but it is not if you have a walking foot. Take a quilt marker and put a box mid way on the top side and stitch it. Just be aware of the bottom and top when you come to the original X stitching that no folds occur as you stitch over it. It will work, I have done this before myself when I thought there was too much puffiness on a pot holder.