That is correct. Technically, you can also do rigid body transformation using landmarks. There is RBF scaling using landmarks and finally there is also RBF scaling using stl.
Generally, the wrap surfaces are defined using some nodes (or landmarks) on the segments. These landmarks are also scaled with the scaling of the segment. So, the wrap surfaces will be scaled accordingly. Please note that the wrap surfaces are analytical surfaces (e.g., cylinders) that are calculated as best fitting from these scaled landmarks. The shapes will not be deformed (a cylinder will still be a cylinder) but only the landmarks used for estimating these shapes will be scaled before the estimation of the wrap surface.
Finally, you can also create your own scaling functions to be used with the segments.