Without wildcards you can't use the automated tool to pre-provision new servers, for example. Say 1.example.com is in production and is to be swapped for new1.

Without wildcards you can't use the automated tool to pre-provision new servers, for example. Say 1.example.com is in production and is to be swapped for new1.example.com which is in staging. new1 can't obtain a useful cert from Let's Encrypt until it becomes 1 in Internet-facing DNS. So you have a service discontinuity whilst moving 1 -> old1 and new1 -> 1 and then applying for the cert. I appreciate that the set of people managing such issues probably aren't the target market ( they also won't be running an as-root tool to make automated changes on their edge servers... ) but it's an example of why wildcards are so useful.