I agree, and will add that this is also a factor at 3-4:00 IWB. Basically the way I am shaped, and do not consider myself to be exactly fat, maybe ~10 pounds over, that the belt is the pivot point in the seesaw, and the barrel has to be long enough that my butt can push back against my gut, or else the grip wants to get pushed out to the side.
IMO a small revolver can get away riding lower to the belt line than is typically considered optimal for AIWB, and with "large" J-frame grips can still be presented pretty well. This also helps with pants with no belt. Also there is another indent in my anatomy, between the hip and the pooch, that the cylinder just drops right into like I was made for it.