I watched Nancy's video, but I still think it might be difficult to get the stitching in exactly the right place if you are doing it from the back.
Part of the charm of these blocks is the lovely curves and scrolls of the embroidery, and the placement of them compared to the applique.
For instance, I wouldn't think if doing the embroidery first, even if it doesn't go over the applique, because it's nice to be able to get the embroidery right up close to the applique where the design calls for it.
I think it would be hard enough to exactly line up the design lines on both front and back, but that is just me. perhaps some of you have nifty ways of doing that.