Imagine this, there is an elaborate crowded background someone may need to write. They are trying their dang hardest to take into account stuff like layering and scale. And then looking into the Preview Window, no matter how much a character in the way back is in their negative nth layer for some reason a couple of character in the foreground phase through them as if they are behind the backgrounder.
Maybe this is my inexperience talking, but it gets very annoying not knowing the problem, if it’s a glitch or just there are some certain characters that may be in different layers than I thought.
Either way, I would want to get some sort of counter (maybe to go along with Spot Directing) which would also indicate which characters (maybe also overlays) are at which layers.