Glad your experiment worked out for you, but just thinking here about the eggs with problem air cells. You said you gave half to your broody. But with bad air cells I usually let them rest for a day or day and a half before putting in the incubator, keeping the turner off for the first three days and being careful of their position. Isn't that something a broody wouldn't do? or would do hit and miss? I have to wonder how much of the broody hatch on the bad air cells was due to luck. Did you mark which eggs were which so you can tell which hatched?Just like with so many other things, everyone has their opinion as to what works best for them. My broody is quite experienced and has a good hatch rate, but I also did not want to leave everything up to her, just in case something went wrong. Likewise, I did not want to leave everything up to the incubator either, just in case something went wrong on that end. Hence, I set half of my shipped eggs under the broody and half in the incubator. (My own version of "Never put all your eggs in one basket.") I also equally divided the eggs that arrived with good air cells, and the eggs that arrived with detached air cells, between the two to keep things "fair". I'm anxious to see which does better in my little experiment... the broody or the 'bator. Only time will tell, but since they are shipped eggs, I'm trying not to get my hopes up!
Whatever way you choose to hatch, good luck!