Hi,
Currently, RailClone's surface tools have limitations. Unlike paneling tools that follow polygons or UVs, RailClone projects geometry along the object's local Z-axis until it intersects with the surface. This method works best when the surface normals point toward the RailClone object, as demonstrated in the attached sample scene.
One possible workaround is to split the surface and use multiple RC objects with different orientations, though achieving a seamless appearance may be difficult. Additionally, you might consider "slicing the surface" to create base splines, but this approach may not be effective in this instance either.
Best regards,