Some award winning quilters shorten their stitch length and sew an exact 1/4 inch seam (not scant) then they press their seams open. This does away with the seam allowance problem because you don't have to account for the width of the thread and fabric folded over. Some quilters think this is not a strong enough seam, but with shorter stitch length, I think it is fine. After all our garments that we wear and wash everyday hold up for years. Some of the Craftsy teachers teach this method and it removes a lot of stress in quilting.