Hello Matt,
You may want to contact the manufacturer of the roofing material. I would try to get samples of the material and then try the detergents that you want to use and see for yourself the response. The company that makes the material probably will tell you what you can and cannot use. We have had some cases where the stuff they said we had to use would not remove the soil!!
Some of the kitchen systems that we do have a rubber type roof on them. Roofing materials do not like grease from exhaust systems. It will also void the warrenty!
We use our degreaser to clean the surface and spray it very lightly. The roofs that we have worked on can be torn with high pressure!
Dave Olson