There's a website devoted to pizza called pizzamaking.com. I found the forum participants very helpful when I first started baking pizza. The Fresh Loaf also has a lot of pizza baking enthusiasts who participate in their forum. You might find these sites helpful.
I don't make deep dish. But I own pizza screens for Neapolitan style pizza. The main purpose of a screen is to crisp the crust. When baking a Neapolitan style pizza, it's also used to prevent burning if the oven is too hot. But I rarely use pizza screens.
I've had deep dish in Chicago, and used to religiously eat at Uno's in San Francisco. Never had a deep dish delivered to my table in a pan with a screen. And pizza crust was always crispy.
Problem with homemade deep dish pizza is soggy bottom. Screens are suppose to prevent that. But the main cause is the amount and type of toppings. Heat releases moisture. Lots of toppings and high heat means soggy crappy crust. My family and friends aren't fans of homemade deep dish for that reason.
Aside from mindful selection and preparation of ingredients to mitigate against moisture, you need a seasoned, dark pan like a Lloyds. A screen won't do much good if the ingredients are all moisture rich and the pan is slow to set and bake the dough.
