I went out and studied the issue of the upper seal moving forward and noted that the seal on the front edge of the slide was crushed complely when the slide was closed, but the seal on the rear edge had a squishy feel to it when the slide was closed.
I decided to try adjusting the stop for the closed position. After some experimenting I ended up adjusting the stops for both the front and the rear about 1/4". See picture below.
This resulted in the front seal having some give and the gap between the wall and the slide was now even from bottom to top. Before the gap was much less at the bottom. See picture below.
Unfortunatly we are finished camping for the year, so I won't be able to report results till next spring.