Let’s Encrypt hasn’t created tools or procedures to provide temporary rate limit exceptions.
The rate limits are described at
You don’t need to obtain a separate certificate for each name. A single certificate can cover multiple domain names, and the “certificates per registered domain” rate limit applies to the number of certificate issuances. Let’s Encrypt allows a single certificate to cover 100 domain names. When combined with the certificates per registered domain rate limit, that allows up to 2000 new subdomains of a single domain name to be covered per week without a rate limit exception.
Hi schoen and thanks for the reply.
I am actually using Plesk plugin for domains, that issue, install and autoupdate certificates. But I can issue only a certificate per domain with that plugin.
These domains were secured with Let’s Encrypt, if I issue again certificates, they count as renewal? In this case should I be able to cover all 30?
Under the current rate limit rules, renewals count against your rate limit but are not blocked by it. That means that renewals should be performed after new issuances.
The current rate limits would allow you to obtain 20 new certificates in a single week, and, after that's done, to go on to renew other certificates that relate to the same domain name.
If you don't want to be subject to these restrictions, you should try to find a method of certificate issuance that allows you to include more than one name in a single certificate. Each issuance event uses resources on the Let's Encrypt end, so the rate limits intend to minimize the total number of separate issuances while allowing people to get the certificates that they need.