I’d think it is. Better if you could also add support for acme-dns, though admittedly the UI to integrate that hook script would be a little more complicated. OTOH, acme-dns lets just about anyone use the DNS challenge. If it’s going to be CLI-only, I don’t know that it’d add anything that I didn’t write up almost three years ago at userguide:let_s_encrypt_for_internal_servers [NethServer Wiki] (though I used acme.sh there rather than certbot–still not a fan of certbot).