When you talk about modifying the frame, you are now modifying the basic engineering of the Jeep's design. That piece is the way it is for a reason...maybe not a good reason, or maybe you could make it better and stronger, but still I don't know why Jeep made it that way so changing it doesn't appeal to me.
Just as a marketing thing, I think you will limit your sales numbers to those folks much more hardcore than otherwise might be interested if you get into frame modifications. If I understand what you are asking, it also eliminates self-install for those of us who aren't up to home welding but can do most bolt on applications.