Q. Does reverse zone support DNSSEC?
DNSSEC is not available for reverse zone of IP addresses assigned by IIJ. This is because the parent zone does not support DNSSEC.
DNSSEC is available for reverse zone of IP addresses managed by any other organization as long as the management source of the IP address supports DNSSEC.
[ Reference ]
Even if the status of DNSSEC for reverse zone is "Enabling," it will not be enabled unless the management source of the IP address supports DNSSEC.
Although there is no problem with name resolution even if the status of DNSSEC remains "Enabling," it is recommended that you disable it because the speed of zone update processing will go up.