Works as aspected! Sorry in French but...






Pinky curve is planar and has same length than green one!
It's the same for you ?

Curious! https://moiscript.weebly.com/uploads/3/9/3/8/3938813/planar_curves.3dm

Pilou,
this is why I am not sure if I am using it correctly.
The unwrapped in these cases are 1 x 1 but if scaled looks correct.
In others they are scaled correctly in one direction only.
Cheers
Barry