Haha, wow, that's a lot of roosters!! Glad you found them a good home!

I love having the brooder in the house, too! It's so sad when they move out and the brooder is so empty and quiet afterward... If I had more coop space, I'd be hatching all the time to prevent that.
Roosters are a whole 'nother animal in the house, though. Last winter we had temps plunge into the negative teens (Fahrenheit) as the high for a spell and I had to bring 6 full grown roosters inside to help with swelling frostbite that they all got pretty badly. There was so. Much. CROWING! It was
crazy! Even crazier was trying to get them back outside, when one of them escaped and then flew from the top of the stairs across the living room and about landed in the fireplace (thankfully unlit)!!

Needless to say, I'm willing to do some crazy stuff to make sure my birdies are safe.
You're fine! The stuff about 2x4s flat side up is very overstated, and not necessarily the truth. You can see in the picture you added that your birds are covering their feet just fine on your 2x2 roosts.