Hi BB,

I did some experiment's with more or less success ...

This is your original setup used on the bodysuit. I have set the 2 in the math node for the fractal sum path to 20 only to have the pattern seam more visible in front. With 2 it's right between the legs.

As I understood we have 3 parts in that setup.

First the fractal sum with companion is giving the needed path.

Second at the bottom the math nodes with v-component. That V goes also to the fractal sum (X) only to "matched" V with the x-y-z coordinates for the visibility at the match point. I'm right.
The visibility for V is running through the complete material group ... in our exercise.

So third at the top we have the u-component and here neccessarily the path from fractal sum is needed to have the right direction for the seam.

In both, 2. and 3. part, the reduction for the used pattern is done. In this case 1/80th to fit nice to the path.