Even with free horizontal movement you still cannot complete the illustrated movement in one Order because the effect says all movement for that order must stop when you reach a level surface. So either it requires 2 order; or you must give free horizontal movement + allow to keep climbing down even after reaching a level surface. Personally i'd go with the second, because while it say movement ends for that Order, it only restrict "keep moving horizontally" it does not restrict "keep moving vertically with their excess movement, climbing down a new edge that was reach because the level surface was exactly 1 base wide." And i would rather have free movement being able to climb a 4" high wall, than force all my ladder-less scenery to be shaved down to 3" height in order to be climbable.
