Avira asked about the proof for the two battei Din. It’s published in the response to the Lakewood cherem from the peshuto Shel Mikra publisher and can be seen through a Hebrew Google to the hebrew discussion groups that discuss this in depth, like the Otzar hachochma forum.
And this has nothing to do with the sefer by Rav Copperman of michlala. That is a different sefer.