I do walk down the midlle of it, you could maybe bounce in the middle without feet loosing touch, but don't think I would jump. Just went and had a look and it has 10 cross bars plus if you count the main outer frame another 2. Then you have the security door mesh over the top of those. At each of the three legs there is 2 cross bars then 2 more spread evenly between the legs. Can try and get a pic tomorrow and throw up.
"I know the Black Widow alloy rack is supported on Rhino Racks. How is the ARB?" The rack itself has a leg kit that mounts directly to the rack.
Lemo.