Could always(make him) put a top hinged chicken wire door over the storage area.

Might need a CW block on nest tops too.
Observe and adjust.
Curious, what are the dimensions of the roosts and board?
Back roost look close to wall.
What is a CW block?
Roost in the big coop were 22” off the ground. I can’t remember exactly how far apart and how far from the wall, but the measurements were based off of the current pre-fab coop. I’d have to measure but my guess is about 8” from the wall and a little over 8” apart for the main coop. It does look close to the wall in the pictures but I’m at work and can’t check
The smaller coop roosts had much less space. We had quite the dispute on order for me to even have more than one roost bar there, because it was initially built with one despite previous agreements to have two. That coop is meant for, at most, five to six chickens for a breeding flock and they will have a pop-door for outside access. With one roost I could have maybe fit three. He also insisted on a shelf that I didn’t want or need above the roosts of the smaller coop area. I don’t have clear pictures of that because I didn’t want the construction materials in the pictures.
I’m not wanting to throw my SO under the bus, because he’s gone above and beyond to build this coop, but there were numerous instances where I’d research an aspect of the build intensely, we’d draw up a plan, and I’d come home and he’d have built something not even remotely close to what we had agreed to build. All in all I am happy with how it turned out, but there are quite a few things that should have been, and could have been, done better.
One more recent discussion was the depth of the poop boards. We had decided on a final depth to ensure they won’t poop and miss the poop boards like they frequently do in our current coop, and then he ended up building them the same exact way as the current coop, meaning when they sleep facing the wall on the outermost roost, they just poop on the floor.
Regardless, the point was more space for more chickens, and a bear- and carpenter bee-resistant coop, and that for sure we do have! Unfortunately I spend what seems like most of my waking life at work where he doesn’t, so most of the burden of the build fell on his shoulders and so much was out of my control.