Just wanted to pop in here and drop a few things I know:
I know a person in Michigan who breeds pigeons. He lets them nest anywhere they want. Most of them prefer his duck shed in the roof trusses. They get along fine with the ducks. He keeps Muscovy's, calls, and common mallard types. They all get along fine.
https://www.strombergschickens.com/category/Pigeons
I once bought a pair of Show Pigeons from them. They arrived a live and were really nice. They too lived with my ducks and got along nicely. Only problem I had with them was their pooping on my ducks at night lock up.
Good to know! I don't think I wanna be cleaning pigeon poop off of my palace trusses tho.
I bet a pigeon would love my set up. But I can imagine it would be horribly messy