Thanks a lot. I never heard about Public Suffix List. From their guidelines: "We do not accept entries whose sole purpose is to circumvent Let's Encrypt rate l

Thanks a lot. I never heard about Public Suffix List. From their guidelines: "We do not accept entries whose sole purpose is to circumvent Let's Encrypt rate limits. They have a form you can use." So probably the best way to go is to talk to LetsEncrypt about lifting limits.