Are you thinking of the kind of crazy quilt that is pieced on a background and the seams decorated with embroidery? The old time ones made with silks, taffetas, ribbons, velvets, brocade, etc. were not intended to be washed. Since the individual fancy fabric pieces were small they were very stable.
Brocade is so beautiful.....I thought about your question and wonder if you have tried using spray adhesive with pellon or tricot on the back of your brocade. Another thought would be to use silk or rayon floss and add tiny stitches or french knots to the surface. These would help secure the layers and if worked among the designs would not be noticed.