Double layers and "clean cuts"
Jean's comment on the differences on right and left (or top and bottom) made me do what I have thought to do for a long time: can the differences be avoided?
So I started with my "normal", looking at both sides:
Seeing that both sides are the same (one side clean, the other jagged) made me suspect that it can't be "fixed", as long as one is interested in a reversible result.
By adding (or subtracting) two ends at the jagged side, one can get clean cuts at both sides.
... but the back will then get both sides jagged:
Personal conclusion: until I feel the urge to take the exchanging layers to twill, I will continue to weave two picks per layer, and live with the un-equal sides because of the reversibility of the result.
Others may have other ideas...