It was exactly the same except that I moved them to the normal direction only. I don’t keep that model, but it’s easy to make a new one with the “MoveUVN” tool. My goal was to keep the control points at those exact locations across the UV coordinate and only modify the N position. But looks like it’s not possible to do so.
It bugs me that the automatic “Match surface” will create a very unnatural looking control polygon flow along those rows of control points. This thing alone breaks the tangency:
