The raised center sections on guide-style devices are to allow you to take in slack on one rope while someone is hanging on the other if you use it in auto-locking mode when belaying from above. It's there for a reason.

Thanks Adam. I have tried other devices and even played with some machine work of my own and found that the teatering action caused by the center web does not aid in rope pull while in auto locking mode. On another note, the reverso ATC does not like to feed my 9.8 ropes very well. The grooves are cut so narrow that the ropes ride almost completely at the top. I weigh 167lb and have to push my ropes through to repel, even with my three year old hanging on with me. I'll be bying a different one and shelfing this thing until I wear these ropes out and go to smaller ones.