Have the game run miscellaneous stuff while there's a separate graphics engine displaying everything.
Toady's already said no to things like this.
It goes a bit further than this. The suggestion is to separate the "backend" doing all the simulation, AI stuff, assigning jobs, pathing etc, from the "frontend" where you actually give commands.
I think it is a good idea, because it allows the player community (which I think includes quite a number of good programmers as this is the kind of game that would attract them, and as also witnessed by helper programs like dfhack, therapist, etc.) to concentrate on making real contributions instead of hacking away at a moving target. Also, after the initial effort it allows the developer to do what he is brilliant at (simulating a dwarven world) and not waste time on things that are obviously not his main interest (UI stuff).
A related model is the linux music system called "mpd" or music player daemon. There is a main program "mpd" which knows how to play music, manage the library etc, and there are many different clients, ranging from command line (mpc), graphical (ario) to andoid app (mpdroid), programmed by different people, which all provide a nice GUI to access and manipulate the actual music player.
Toady: everyone loves your game and 90% of those people have lots of interface frustrations. Please allow us to scratch our own itch by separating the game into backend and client and open sourcing the client. The client is really not your business asset (the backend is), so there is little business risk. I would happily donate / pledge a kickstarter to get this done, as I think this game has much more potential than currently utilized.