One of my inspirations for getlocalcert is a tool to make DNS-01 easier.

acme-dns let's you add a CNAME to another DNS zone, which let's you issue certificates for the former domain name using a convenient API for the latter zone. Seriously read about it, it's awesome.

https://github.com/joohoi/acme-dns/

That tool is open source and self-hostable. getlocalcert also provides this feature, but as a hosted service. Choose the method you prefer.

https://docs.getlocalcert.net/tips/validation-domain/

Once DNS-01 is easy, wildcard certs are easy. Here's the docs for setting up a wildcard cert via getlocalcert: https://docs.getlocalcert.net/acme-clients/lego/