After Enhance added support for the “DS” record type, I am now able to sign my subdomains as well, although this still has to be done manually.
First, DNSSEC needs to be enabled for the main domain, for example, "domain.com", and the DS record must be added at the registrar, such as Namecheap.
Then, DNSSEC needs to be enabled for the control panel domain or any subdomain website, which in my case is "cpanel.domain.com". After DNSSEC is enabled, the DS record can be copied by clicking “View Raw” and then added to the DNS zone of the main domain.
The only remaining issue is the phpMyAdmin domain. It does not allow me to view DNS records or enable DNSSEC, which forced me to use phpmyadmin.secondarydomain.com, where DNSSEC is not enabled. It would be great if I could enable DNSSEC for the PMA website in the same way that I can for the CTL website or a normal website.
Since I do not use Global Webmail, I have not tested whether it allows DNSSEC or not.
I would like to request that, when DNSSEC is enabled for the primary domain, subdomains created under it should automatically have DNSSEC enabled as well, and their DS records should automatically be added to the main domain’s DNS zone for ease of use.
This would be especially helpful for users who use staging domains, as they currently need to manually create the DNSSEC entry and add the DS record to the parent domain every time in order for it to work.
Hope this helps.!