I actually prefer having most of my pigeons breed and nest in open lofts so as to give them more space and free run of the loft, as they are much happier this way. I closely monitor my birds and know their personality and temperament. I will check on them often and watch them to make sure everyone is getting along, no pairs show any signs of cheating on their mates with another bird, and I will make sure that the pigeons can live in a peaceful environment with no stressful and troubling bully pigeons or other problems. The breeding lofts are also never overcrowded and each pair also has a large compartment to fully claim as their own territory and nest in. 95% of the time scalping occurs in breeding/nesting/fostering lofts with overly aggressive pigeons or in lofts which are too crowded or do not have a very good setup.
I have had two problems with scalping, but they were both from predator attacks (lucky pigeons, both of them survived and are living happily now) and not from other pigeons in my lofts. I will not stand overly aggressive birds and will re-home them if they are the main problem. There was another instance which almost became a scalping problem - a young Parlor Tumbler pigeon being cared for by Homing pigeon fosters fell out of their large nesting compartment onto the lower platform entrance of another nesting compartment while trying to explore. The parents of that compartment chased the young Tumbler around in the compartment for however many hours and pecked off most of the feathers on the top of his head, but no blood was drawn and no one was otherwise injured save for a terrified young Tumbler. That was my fault, and I should have removed the Tumbler from the fosters a couple of days sooner before he had the urge to explore too far out.
My point is, open lofts are not always a bad thing and if they are setup well, not crowded and the pairs of pigeons are monitored, your birds can usually be much happier in a harmonious open loft than a closed loft (besides some breeds of pigeons who do better in smaller spaces anyway).