The greatest stretch will always be to the outside of the pivot point. So IOW if your fulcrum is on the underside then the stretch will be on the top.
When I do fulcrums I always try to move the fulcrum in and out so the stretch is broadened over a larger area then just one spot.
I haven’t seen any change is curvature but I think you could bring about an increase in curve if you concentrated on one fulcrum in the direction you want to emphasize. So if you wanted more up curve you would do fulcrums on the top while hanging SO or SU. That would stretch the bottom side allowing for more blood and tissue on the bottom side forcing an upward curve. The same thing could be accomplished with clamping and while fully engorged carefully do bends of the shaft in the direction you want the curve. And I do mean carefully because that would be so intense. Damage can occur easily if you go overboard with that one.