I too have several "tribes", which, with a little observation is clearly obvious. I loved the way you're experiment played out. Thank you for taking the time and sharing your results. I believe you are on to something with this! Great work!
I too just had this same experience. Each nest I have found in the last 3 days has had a minimum of 14 eggs. My newly laying Easter Eggers are HOARDERS! We too have set up "bait" nests inside the yard and just outside the coop. As of today they are still free ranging all day, but this may change for a while as well. We keep several roosters within the flock and that is my main worry having then locked down in their yard all day. I don't have rooster problems now....and don't want to start by forcing confinement.
Those nests are amazing. A nest that has truly been made by the bird is so beautiful. Your pics make me want to set up nests in the coop that look like homemade nests. I wish I had taken a picture of the first one I found.