Antwerp pullover blending sizes

I am struggling to figure out how to blend sizes for the Antwerp pullover when the center front and center backs are different for the different sizes. I need to go from size 14 shoulder to size 10 waist/hip. If I blend the center lines (the fold lines), it will become a curve and I won't be able to cut on fold anymore. Is there another way to blend sizes? Perhaps cutting the larger size and reducing it at the size seam? Any guidance would be appreciated. Thanks!