I think we could fork this, update it to use PHP 7, and swap nginx with Caddy:
http://www.sebdangerfield.me.uk/2012/05/nginx-and-php-fpm-bash-script-for-creating-new-vhosts-under-separate-fpm-pools/
My idea is to setup a similar nginx structure (e.g.: /etc/nginx/sites-enabled → /etc/caddy/sites-enabled), so it would be easier to swap it.
I’m also considering installing Caddy following the instructions here, to keep things “maintainable”:
https://github.com/mholt/caddy/tree/master/dist/init/linux-systemd
Would anyone be interested?
Edit: I’ve started working on it, currently rewriting the template files into Caddy format 
Edit 2: Managed to get a prototype working, just need to test it a little bit more before making a Git repo. Any name suggestions?