Its currently possible to make a point at the intersection of a linear entity and a plane, but not at the intersection of a spline and a plane. This makes construction of lofted objects using splines for both the sections and the rails very difficult. There is a workaround, or what should be a workaround, by making a square section body using the linear splines and intersecting the planes with the body, then creating points where the entities created intersect the normal plane, but the points don't seem to be on the spline, even though it reads as coincidental.