Has anyone ever used or seen a run with two levels on it? I am considering making a run that is 6 foot tall, 5 foot wide, and 6 foot long. Then divide it horizontally, making two runs that are 3 foot x 5 foot x 6 foot, one on top of the other, adjoined by a ramp. The top run maybe half of it being made into a shallow trough with dirt/sand in it, the other half being hardware cloth. The bottom run being a normal run. Any thoughts?