Just my opinion here,,,,,,,,,,,,,,,,,,I don’t want them attracting more raccoons, or worse a hawk, with their presence. I love free ranging my chickens, having pigeons flying around attracting predators

I don't think it is valid to say you would be attracting MORE predators.
The predators are already present, and are opportunistic.
A raccoon will visit, your coop, and if he can't get in,,,,,,, keeps going. A hawk can see your chickens and other animals from much higher up, than you can see hawk.
Only suggestion to keep the ferals out of barn,,,,,,,, is to block the entry point. That may not be an easy task. I personally would let them live a feral life inside barn, and let nature rules guide. If you do get your pigeon housing all sorted out, then you may decide to keep them there.
Most of the readers here know that Caveman and ferals are

I view them as equal living things to the thoroughbred racers, that are better in health and condition,,,,,,, many time due to the excellent care provided by the owners.
Don't be shaking in your boots worrying about diseases being brought over. (including lice, and mites,and fleas),,,,,, You may try your BEST efforts, and these still may arrive.

If you do encounter such, there are remedies for them.
I have read enough posts with chicken keepers encountering parasites, and diseases, with no clue where the source came from. Wild birds, and the wind will bring many things to flock, as well as people. Good nutrition is a very HIGH KEY , to immunity from many of the cooties present in the environment.