Hmmm, that's not a bad idea. Prevents anyone from getting a nasty surprise from above if they poke their head out while nesting. And it would leave some room to mount a curtain.
We're intending to move on from our Omlet Cube and build a coop next spring. I have an idea in mind that I haven't really seen it executed. Poop shelf is a must, but is there any reason the nest boxes shouldn't be under that shelf? I suppose a chicken could perch on the edge of the poop shelf...