when I was a kid there was a small chain at the top of the screen door to prevent the screen door from swinging out too far. They still sell that stuff at hardware stores. Also, they sell those door dampners that you mentioned as replacement parts and you could add one to your door. I had to move the one on my unit as the factory put it on so that it did allow the door to hit the awnings arms... moving it fixed that problem.
2014 Shamrock 183
2014 RAM 1500 SLT Crew Cab HEMI 3.21 8 Spd 4X4