I'll just accept that there are no (efficient) solutions on this case.

The Loft tool doesn't work in many way. Even if I loft 2 curves, the geometry becomes huge, it does not become a regular shape following the normal terrain slope and once I get to a point when two pieces of terrain at higher elevations diverge, then it gets impossible to loft higher than that.

I'll be switching to Windows next year, and that will take care of many problems i've been facing during my 7 years of AC Mac.

Thank you all for the trouble.

L