Well, I will make a flat cover on my own, exactly as I need for my project, I do not expect RF elements to manufacture or design it for me. The only information I need is if the rounded form makes any difference for the antenna performance, which I have actually not expected. Protecting from the weather and birds would also been done by any shape. So if the shape is rounded for optimal RF performance, then how is RF influenced by it, when the cover is dielectric?