Today, I was trying to get a certificate for my server which uses the dynamic DNS server dynv6.com but I got the error messages that already too many certificates have been issued for all its (sub) domains which end with “dynv6.net”. It would be very good if for such services a different limit than for usual websites would exist.
To expand on the issue a little, below is a link to a previous comment on the topic.
So dynamic dns services that want to allow creation of (more) letsencrypt certificates for subdomains of theirs can request their root domains to be added into this list: - View the Public Suffix List