After last iteration of Leash testing and fixing all worked well and everything was working properly, after some time (I went away for a few days). Upon return noticed all nodes "chunter" service was in maintenance. Upon quick inspection it appears that some kind of run away process was in effect as per monosnap screenshot. I have fixed 1 node to get chunter out of maintenance by disabling chunter and epmd and killing the chunter processes. After this I could get it back up and running.
I have left the other Nodes chunters still in maintenance so that Kevin or one of us can take a look so we can trace the root cause and confirm if it is indeed Leash related. We should be sure of this prior to "Leash release".