Lets Encrypt subdomain template

Is there a way to specify a set of default subdomains that should be secured using Let's Encrypt?

Essentially, we are testing out various cPanel alternatives and are looking to configure a serverwide installation of Roundcube and/or horde and want a way to secure all webmail. and roundcube. subdomains of all virtual servers created on the server.

I know these can be manually specified after the virtualmin server is created in the lets encrypt section, however, I want them to be the default in some way. Is this possible?