I don't know if this will help, but I had a bit of an epiphany regarding my hens' pen today. Normally, they're free to come and go from the pen and connected coop to the "chicken yard" all day long, so I haven't put a lot of thought into how the one's configured. However, I was going to be gone from 5 to 10 pm tonight, so locked them in the pen before I left. They were pissed! Even though I threw in some sow bugs to distract them.
As I looked around the pen, I saw that while there was a fair amount of clutter, it wasn't very useful clutter. The only things that really get used are the roosts and the substrate - lots of fluffy stuff for scratching and pecking. By contrast, there are several "rooms" in the chicken yard that keep them busy and separated all day long - an A-frame tractor repurposed as a chicken tunnel; a mound of Virginia creeper on an old compost bin: an old willow surrounded by lemon balm; a stump room (three stumps, a couple chairs, shade cloth and straw); and other shade-cloth-covered areas with things like a large dirt-filled planter, a sand bath, a small table, a mound of dry leaves, etc.
I won't be able to duplicate that in their 8x16 pen, obviously, but I'm going to see if I can come up with ideas for mini-rooms in there, too. Definitely some stumps, a pallet or plywood on cinder blocks, another dirt-filled flowerpot, etc.