Yes I would like tat, in fact I would like it a lot. But I understand why they didn't.
The system right now uses premade maps. All stored on our own systems. So the data transfer to and from is easy. A system like you describe would use up a lot of extra data to be send back and forth the client. They really want to be sure that their systems can survive the current load.
Then there is the bugging problem. Notice how easy it is to make a bugged arc? Add bugged maps to that mix for extra fun.
I think there is a lot of stuff they need to work on to make this one happen.
What GrinningSpade said. And specific spawn locations... The more I think about it the more wrong rhe idea seems. For a huge part of game everyone and his dog uses, and probably will use, foolproofnes, lulzproofness and not making farming too easy, are more importaant than the ability to spawn that boss exactly where you want him.
BUT! While potential spawn sites and front/middle/back areas should be computed, author should see them. That way you can tweak your map to make that all-important boss appear at specific location, but not to make your own Atta Cave just for lulz or by accident. (Oh, I soloed Atta cave and liked it, good test for a newb ghoster/"there was an EB?" toon. But if every arc will be like that, it would become uncool.)
And frankly, I would agree to just, say, Longbow set with the ability to change group symbol on the walls and repaint them. Would allow 90% of things I'd personally like to use map editor for (like better Council/5th-themed maps. Or Malta having their own maps insted of squatting council bases. )
The problem with a map editor is that it's a massive undertaking: about the size of the base editor or the mission architect itself. So, while I'd like to see one, I don't think it's something we can realistically expect to see anytime soon.
(if this is in and by some amazing fluke I missed it, then disregard the rest of this post)
The thing that's missing most from MA, as far as I'm concerned.
I mean, I'd love the ArenaA that I wrote in the other post, the 100kb limit is a little low and power/health frequency/ammount neeeds to go in at some point, but I'm amazed this isn't in. It's the first thing I thought I'd see.
You wouldn't need to make it any more complicated than timesplitters. Only allow indoor maps.
Let's say we have several main tilesets - some, if not all of which could be purchased with tickets.
Things like Tech lab, Warehouse, Caves, Sewers, Offices and Arachnos Layer. Even Supergroup would be a cool tileset.
Then you have pre-made rooms. Things like single-tile peices (short corridors or corners), ramps, large spaces (especially in warehouses), tiles with double layers, etc. You pick them up and put them where you want on a grid, rotating them as you go. Tiles can only connect at set points, and if they don't connect then that part of the tile gets blocked off.
Maybe have one or two 'outside' tiles, which can't be linked up directly, but give a nice outdoors area to play in.
You have a symbol for 'enterance' - where players spawn. You must have this in your map, and it can look like whatever you want.
Then you have little symbols for Enemy spawns, Ambush spawns, Boss spawns, etc.
These would spawn the key object at that location, then try and put any extra enemies as close by as possible.
You could probably even allow them to be named, which would allow you to place things with precision (rather than front/middle/back)
Then you can create extra floors, maybe even allow a second tileset to be used (no more than two would probably help limit memory issues, but I don't know)
Then you can put in doorways. These would need to be linkable. Different doorways could be selected. Things like lifts would have to be placed to linking areas so that they can be outside the map.
Finally, you have special peices.
Things like jail cells (which automatically suit the tile set, with matching doors) and respawn points (where you go instead of hospital, obviously can be placed in the jail cell, but so could allys).
Maybe, like Timesplitters, doors could be placed where tiles are linked. These could then be set to open as a clicky, triggered by an in-game event (like destroying a generator), or told to stay closed.