Map curve to surface precision

Hi Guys,
I am trying to use the map curve to surface component as I would use the UV unwrap and remap command inside Rhino. Pretty much I am trying to map a curve pattern to a surface in GH. Everything worked well. I had to rebuilt the curves with mor controlpints to make the maped curve stick closer to the surface.

My question is how i cant get it to be more precise. If I unwrap the surface in rhino and then map the resulting curves back onto the surface in GH the created curve are not on the edge but a little Offset. I hope you guys can help me. Thanks Oliver