A lot of effort in Molflow or Synrad is in selecting the correct groups of facets and checking to make sure they are setup correctly. I think it would be nice if you could colorize facets according to whether they pump, transparency, material etc. When you first import geometry, all facets would be white as usual. As you go about setting up your model, they would colorize according to your settings. You could come up with some default colors for various types of facets or value ranges. But it would be good if the user can change those colors if needed, or provide a text file to customize them. Also if this were implemented, it would be great to be able to select on those colors. This would thus also serve to group facets conveniently as well as make it more clear what is going on in your setup just by looking!
-- James