Ok, I know that the bottom screw attaches to the chassis and as I said (well, maybe not clearly), I took the side screws out completely to see where this angular adjustment is at and it was a pain to get those screws back in that little block that rides in the channel in there.The angular adjustment is mild, it's not a big incline, but it's there. The bottom allen screw attaches it to the chassis and the side allens adjust the front to back and angular positions.
If there is angular adjustment, its either very small amount that's not real useful or I'm still missing something on this.
So, to get to this angular adjustment....you loosen the side screws and tilt it then tighten? If so, I don't think this is an actual designed adjustment and would be more along the lines of taking advantage of the clearance between the rider and that little block in its track.
I don't think (but I'm often wrong), this answers the call for a wedge like bag rider.
Cheers guys and thanks for the replies.