Well, I do not play 4e and am unlikely to do so. This might put me at a distinct disadvantage, however, if there were enough details so I understood how and why these features were useful and needed I do not see how a map is not a map. In other words, so long as everyone knows what the goal is there should be no problem. If the judging is seriously impacted by the fact that a tree stump is strategically placed so a fighter can dive behind it on his way toward a fire breathing dragon it might mean that those who have no clue on 4e will be less likely to win. Is there some reference for folks who are interested in making maps for 4e but are not players of the game? For instance, Gurps Lite is a short form of the Gurps rules and is free to read. If there are any examples of maps that are good for 4e gameplay that would be helpful I think.
I know that in Gurps there are charts for all kinds of cover and body positions during combat. Is that anything like what you are talking about? Obviously when I play I use GURPS.
You mention "large open areas" which seem to me to indicate armies at battle. The more tense movie scenes I think of are a couple of swordsmen going at it on a narrow walkway with nothing to keep them from falling so I'm not sure I get it. Unless you just mean a lot of ground is covered during a battle? I totally get the things for monsters to hide behind, hazards, etc. At least I think I do.
I'm game to try anything with a few exceptions. I just hope I don't get blown out of the water because I had no idea cranberry hats were some sort of awesome shield against buffoonery.