Before you hack away on your hammock please make sure this will solve the problem. I'm not sure cutting off the edge will help as much as you are hoping. I think you may have to cut off the ends & change the way the material is gathered to remove the extra sag from the body. I'm writing this knowing what I am saying is as clear as mud but cannot think of the right way to say it.
What's in my head originated from this thread:
I think some of the SB Pro's may have a little too much of a convex cut making the sides too high.