Since you have gone to so much work sewing your quilt of double wedding ring, I would highly recommend looking at how others have finished the edge. Personally, I do love the 'rounded' look to keep the wedding rings appear to just 'fall' off the bed.
Agree with Holice - highly! Wishing you much happiness with your final decision! Photos when finished? And a note as to why you chose the way to go that you did?