one addition I thought of just today was the visibility category of the editor. Perhaps the ability to toggle the visibility of volumes could be useful, as they tend to clutter the screen and can overall be obstructive.
This addition would be a little larger, but I feel a cooperative editor (with a limit of roughly 4 people) could be beneficial to larger projects, especially levels of the large and insane size or levels of very high detail.
Molton is right, the settings already exists, though it could use some improvements. It would be nice if the new visibility options had similar customizability as the devkit options. In particular it would be nice if we could toggle the wireframe’s depth settings, seeing bounds of water volumes through the map is quite annoying. Also, when water volumes are set to hidden, the surface also disappears, which isn’t ideal. It would also be nice if the material on the surface of the new volumes was unlit, since seeing them shaded looks really weird. They are also not ignored when baking the GPS or chart.