That was possible with 3mx format but now is lost with 3sm. Regression.
Also option to load some vector format on top of model. Desktop viewer is most convenient way to deliver results as iTwin publishing is too restrictive and doesn't allow local coordinates. Users love Desktop viewer because it is so intuitive and easy to use. Unfortunately we are still stuck with Update10 version as newer versions require Bentley account which non-Bentley users don't have.