It's not always 1-level. Exit may spawn in the northeast-most corner. It would be good to finish the path exactly there as the exit is extremely hard to explore using explorer.
The Battlefield bridge maps is like the prison maps. There is 3 different variations of them and the largest of them is always one map. I'm 99% sure of this. But you're right. I should make waypoints all the way to the usual exit portal for the smaller variations.