Filght Ready Quail?

I am new to the quail business. I am getting ready to start raising Japanese Quail for bird dog training. I have learned that they mature quickly and are laying eggs at 6 Weeks old. At what age are they ready to go into flight pens? I plan and brooding them for 3 - 4 weeks in a brooding pen then placing them into a long crate 24inches long x 10 inches highx 12 feet long. 1/2 inch hardware cloth on bottom and 1inch chicken wire on sides and top. 26 birds to a cage. This way I can max my heated coop by placing 8 total cages (200birds) into my 15X20 heated coop until it is warmer and then move them out in the long cages. I will have the cages on wheels to be able to move them around for fresh air and sanitation during the warm months. When if ever should they be put into the flight pens? Do they need to go into a flight pen?
Thank you for your response