Acutally, I investigated the possibility to use Axem's prompt-box script to simulate an old school dungeon crawler some time ago (for investigation of a ship's interior). Didn't get to combat, but alternating activation turn based is only as complicated as you want it to be, so....
... anyway, the proof of concept worked, but it gets complicated because you actually have to build the map outside of FSO, and same goes for a combat engine, I guess. Then to get it into a mission you would have to break it down into variables that codify gamestates etc etc and than just run it. The work is very disproptionate to the effect