The only problem I can think of, even with an 11 foot wide lift, is that you don't want to be too close to the edge of the slab since you're putting a rather large portion of PSI near the edge. I always thought you wanted to stay 1-2 feet off the edge...at least according to Rotary.
This puts you in a bind since now you need an even narrower lift.
If other have done it, I'd ask them how thick their slab is at the edge and how close they might be to the edge.
SCA037, how about you?