@johnpoz I'll describe in another post how I setup the ACME thing; works just fine on one machine, by the way. Used a non-privileged user with sftp into a chrooted enviroment. So unless chroot and/or scponly are broken, this should be rather safe an approach, at least safe enough for a machine which needs its admin interface open to the internet anyway, because it's on a colocation site far away from where I'd have physical access. (The machines mostly act as VPN-based routers, FW is just an added bonus)
So DNS is way too complicated, until it's migrated, as it's still self-hosted on an old computer, and the various automated DNS interactions aren't an option there...