I think that a topic about editor enhancement requests could be useful, since the editor is great, but can be difficult to master it. Especially when few things could be improved for the sake of the modder.
I used it for a while now, and tried to make atmospheric dungeons, with odd walls and rooms, strange proportions, lights and so on. We can have different stages inside a level, floors above other floors, ...
I started with general shape of the level, so with just floor elevation and ceiling elevation. And it's a pain in the ass. Let me be honest : the way the Editor works is good, but it's difficult to know where the floor is (0? -5? -4?) or the ceiling. As the "undo" function doesn't exist, it's really difficult to build a level with good floor/ceiling elevations. We know the X,Y location of the mouse, it would be great to have also the elevations next, so 4 numbers: X,Y,FLOOR,CEILING. Is it possible to do that?
Other thing : Alongside the items/elements of the assets, you have small icons on the left. Filtering the icons would be great.
Last thing I noticed : Working with layers would be really useful : Isolating elements/items as we want could save a lot of time to focus on gameplay/reward/item and so on, we could isolate areas (if we want to test the level without monsters for example, or without the boss), etc.
Last last note (
) : An actual "feature" that is annoying. the party is somewhere. It goes in a room that has -2 in elevation. Each time I refresh, the party is in elevation 0, and fells on the floor. Irritating, after a while. 
