Spruce Pollen and Metal Roof

Hi, I just installed a brand new metal roof on my house and garage and would like to plant spruce trees as a sort of privacy fence near by. I have heard that pine pollen can damage or at least adhere to a metal roof, and I was wondering if spruce pollen can do the same. Additionally, can someone tell me how far from a metal roof a spruce tree should be planted? I do not have much room. Lastly, if cleaning is needed, how often will this need to be done? Thank you for considering my question. Jon