Excellent move by Dan Griffiths, I hope it goes well. I've started a project with similar goals for my own needs and I really don't understand the negative posts above. It TOTALLY makes sense to use WP as an OS admin interface to end up installing, in most cases... WordPress! Sure, there will be unique challenges bootstrapping WP to mange the underlying LEMP (in my case) apps but nothing that cannot be overcome. The absolute number one reason to compete with cPanel/Plesk is that they are proprietary non-free non-open abominations locked up behind paywalls. If it's not on Github it's not worth using. End of story. Well, there are more good reasons why WP makes sense for this kind of application but that is the main one. Next most important reason is the consistent WP admin interface and a zillion plugin developers already familiar with it so OPEN SOURCE addons could flourish. No longer locked into waiting for cPanel/Plesk to pull their fingers out and update some important feature... nope, just rock up to the codex and have at it. Not happy with the way your current panel looks?... why not be able to chose from 100s of admin plugins and themes?

Just go away and give me a WP based hosting panel option 10 years ago already. I'll contribute to the HostPress project even if I am writing my own (probably much) simpler LEMP version just for LXD on ubuntu servers.