Deprecation notice force BIND 9.20+: dnssec-must-be-secure option

Hello, in line with out deprecation policy, I am notifying the mailing list about our preliminary intent to deprecate the 'dnssec-must-be-secure' option. The option will be marked as deprecated (causing warning from named-checkconf) in BIND 9.18 and 9.20 and it will be removed in BIND 9.21+ when

Multiple master servers for the same zones

After some recent upgrading it was discovered that both DNS servers were configured as master.  I'm assuming i can use  https://kb.isc.org/docs/managing-manual-multi-master to "demote" one of them but is there anything to look for concerning possible inconsistencies and how do I check for those