It takes a test, so players can do it more often (ob 2- few rooms plus personally surveyed) and suffer more conditions, or put it off until its convenient. (whole dungeon level! ob4), right?
Let’s say there’s a hazard on the map, like Gaping Chasm, ob4 Dungeoneer to cross, or zombie horde we had to Run away from to get past. Do the players have to have a ‘safe’ route to where they want to go on the map, or does having the map allow them to safely circumvent that hazard?
I assume I could, if desired, use a twist to establish a break in the safety of the map up above (the player’s don’t know it know, but on their way out of the dungeon, something bad will happen! mwah ha ha!)