Grid tile problem

Hello everyone,
I would like a clarification (if possible) regarding a recurring problem: in a situation where I have to project a grid onto a surface how can I avoid that the stitching of the surface compromises the repetition of my grid?
In general, how can I create continuity in a grid projected onto a surface without noticing the start and end of the projected grid?

I attach rhino files and grasshopper files in order to better understand the problem, I hope it is understandable.

Seam problem
Paralume.3dm (3.6 MB) (14.8 KB)