Assuming I will never host more than around 30 different domain names on a specific ISPConfig server (with just 1 IPv4 address), totalling to a maximum of around 95 certified names ( when all subdomains are counted, like mail.xname and somethingspecial.xname ) is it safe to say that I can use just 1 big cert for all ? If so, such would ease my configuration by a huge margin. That way I can extend the one cert each time a new Client is added, and have Clients able to securely use mail.my-private-hosting-outfit.org as well as mail.clients-domain-name.org to access their mail. LetsEncrypt are not really saying this is either a good or bad idea, but I want to know what you guys think. Thanks in advance for possible assurance on this.