I used two pathfinding behaviors for the enemy type. Pathfinding & Pathfinding2
I set the cell size on 32 for both, and set buffer size to -16 and -14.
I set different obstacles for each, and only have one turned on depending if the enemy is flying or not. when the pathfinding is turned on it looks for obstacles depending on the pathfinder used. This generates two different pathfinding maps. But like Ashley said, this is kind of a hack.