Why it is still not possible to import a SW part with the planar sketches?

            Planes can be imported and I wonder why the planar sketches cannot be imported. Is there any principle difficulties or it is just a matter of coding this very needed capability, especially  for automatic rebuild on constructions done on the top of imported part with planes and sketches?
- Of course under hypothetical assumption (another problem with SW) that those construction will rebuild if the imported part is substituted by another part of the same topology, same planes and same topology plane sketches with different dimensions.

SolidworksImport export