Wow looks great! That should really help keep your birds occupied.
What breed is your bully? Just because I'm curious.
You could also release some crickets or worms into their enclosure(I'd give the worms time to hide before releasing the hounds lol), small grass clippings, melons, pumpkins, tomatoes, squash, zucchini, hang a cabbage(green only as red/purple makes their outrageous colors- I believe it's blue but idr), apples-make sure they can't pull down eat or get tangled in what you use to hang it
Hanging smaller items are great bc they move so take longer to consume and are more engaging. If you have a bully and want to hang an apple I would recommend hanging two apples so the other birds have another one if she doesn't want to share.
You'll find many many ways to keep them busy and happy on days off of free ranging. Just make sure any treats or produce they don't eat isn't left in there to rot as it could make them sick. Then again from our own experiences chickens don't really understand the concept of leftovers unless they don't like something.
Bananas, ears of sweet corn that were shriveled, weeds that have been pulled, tomatoes, carrot shavings, bell pepper insides, strawberry tops, old dry bread, home made and boughten flock blocks. There's loads of ideas.
Most things can be offered to them as long as they're not moldy or rotten. Ours love bbq and fat pieces out of the slow cooker. Lol
Just make sure it doesn't make up too much of their diets and they don't put on too much weight.
We give our flock lots of treats during yucky days they can't go outside in especially in the winter. Wisconsin winter's can be brutal. Bored birds leads to all kinds of problems including egg eating, feather pecking, and cannibalism. Besides keeping them entertained is so much fun.
We generally stick to the first list I made for days we're worried they'll be really bored. As they tend to last the longest. Of course if you have to buy the items it can get expensive. Pumpkins are usually pretty cheap and if you break it in half they'll love it.