I'm happy to see this thread and maybe its time for us to do more tests on whether the dns clustering features is suitable for servers with reseller accounts.
When we previously did testing, a reseller on one hosting server in the cluster was able to wipe out the dns zone of another reseller on another server in the cluster by simply creating an account with the same domain then terminating it. For this reason, using our clustered dns servers was not an option for any server with resellers.
EDIT: In addition to the above, I'm happy this problem is finally getting looked at almost a year after I initially reported it via the ticket desk in great detail and was basically told we had to trust our resellers not to do this.