When I use intersect command to get a nice 3d curve I'm getting incorrect results (Windows 10, locale set to pl_PL).
The resulting curve usually has some overlapping segment which totally messes things up. It seems MoI has issues with intersect when the result should be a closed curve.

I have a short video recorded (13 megs), but the forums do not allow me to attach it (I'm getting 500 Internal server error).