Thoughts on run for brooder area.
I have a separate run off my brooding area and I really like it for several reasons.
Gives the chicks more space.
Teaches them to navigate a ramp and go in and out of the coop....
...before they have to do so while also navigating the adult birds after integration.
Gives more space to the whole flock once I take down brooder partition wall.
Looking at your plan, you could flip the whole scenario, having the brooder on the side where the run will be. The pop door would be under the roost board.
Oh, and, also wanted to suggest you make your roosts/boards in 2 separate units, mounting the roosts the the boards. Worked very well for me when I had to remove the whole shootinmatch to repair the longer board...and when I had to remove the shorter board to repair poop door rope. I didn't really plan the two separate units to begin with, but added the shorter one later and it has worked out well. I like to make stuff easy to remove.
Oh, andand, door to run. My run access door(also a dutch door) is not out of the coop, just wouldn't work, but it's close to door into coop and has worked out just fine.
Sorry, rambling this morning.