I remember something about an option turn_limit: -1 to shut off turn limits, I went thru a phase of "can 3 archers win the scenario" and the answer was often yes, but it sometimes exceeded the totally arbitrary turn limit.

You can create a whole new game out of the intended game that way where it turns into something like a counterinsurgency game where you battle for the hearts and minds (well, at least the hearts) of the gold generating villages.

There's a lot of interesting railroad track in the game, but if you step off the tracks there is also interesting land that doesn't have a track on it, thats not even on the map. It can be turned into an imperfect sandbox, and that itself is a metagame to find the "best" way to convert it.