Dometic ac with heat element and Maxxfan 7500

I knew I wanted ac in my second van and a maxxfan. It was a struggle to decide where each would go. I know now that I could have moved the ac or fan more forward and to the rear of the roof because the 14 inch limit for the opening was needed. I think I could have used the area between the ribs that were just under 14 inches...anyone know for sure? I used 1/4 inch aluminum strips cutout for the valleys on the roof to add strength to the edges where the ac would sit. Using a base of roof gasket and then eternabond over the aluminum extending over onto the roof and then inside over the 2x4 (cut smaller) to the start of the ribs. I did not want any possible leaks in the future to weep it's way into the layers of the ceiling panels and insulation.