Wow Michael thank you, it works exactly as I asked.
Using a simple big plane as 1st set, and all the objects as 2nd set, the result of Intersect Curve is an easy way to get zero-depth sections.
It generates curves of intersection between objects, here's an example with a plane intersecting a second set of 4 spheres - only the plane is intersected with the spheres and not the spheres with other spheres, that's the difference from the regular Construct > Curve > Isect command:
This script is useful to quickly make zero-depth sections of the model, by intersecting with a simple plane.
I hope that in the future we will be able to get projected lines as well (of the elements that are not sectioned).
M.