Let’s Encrypt now supports Wildcard Certificates and LE4D will support it too 

By Detlev Poettgen | 3/14/18 11:21 AM | Infrastructure - Notes / Domino | Added by John Oldenburger

We’re pleased to announce that ACMEv2 and wildcard certificate support is live! With today’s new features we’re continuing to break down barriers for HTTPS adoption across the Web by making it even easier for every website to get and manage certificates. Wildcard certificates allow you to secure all subdomains of a domain with a single certificate.