Holy smokaroonies, that is the most beautiful setup I have ever seen!
And I am delighted with your "salad bars"! I am planning to build some pens for my breeders, but was feeling horrible at depriving them of fresh grass. By putting a small frame in each, that problem will be solved, and I can also use mobile frames to help re-grow some of the weeds'n'things in the bare areas in the main chicken yard. Plus I bet your gravel idea would help big time with our winter mud issues. Hooray!