I was looking at the X-FS video again yesterday (its like jetski porn to me...) and I was checking out the the pump and intake placement, but also the angle in the rails like you mention.
I imagine that you could lightly cut the 90* bend on the bond line, flex/bend/flare the part that goes vertically to a 45* angle or so and re-glass it so its super strong. Might be a good use of the 2" tape that UScomposites offers?
Tom, do you think that would be enough of a change to alter the handling and stability? Actually, looking again, the XFS bond line has an angle from the front all the way to about 3-4 inches from the back, where its more horizontal and has a little kick upwards. Hmmm...