Distance spheres, shadow cones, surface feature labels all currently can be set differently in each viewer window.
However the "Surface Image Model" currently changes across all open 'viewer windows' (SN7pp, SN8p, SN8pp confirmed behavior (link))
Comparison of different surface models would be vastly easier by being able to have each viewer window be able to display a different "Surface Image/Model" of the solar system body being viewed/studied.
Here is a video album showing the current behavior:
https://photos.app.goo.gl/fWFBwfz2wtY3LULJA
Thanks!