OK, this is a weird post, but after reading a post about running emacs with systemd, [1] I've realized that the my take on how I run and manage processes is a bit unique, and worth enumerating and describing. The short version is that I regularly run multiple instances of emacs, under systemd, in daemon mode, and it's pretty swell. Here's the rundown:
On Linux systems, I use a build of emacs with the lucid toolkit, rather than GTK, because of this bug with GTK, which I should write more about at some point. Basically, if the X session crashes with GTK emacs, even if you don't have windows open, the daemon will crash, even if the dameon isn't started from a GUI session. The lucid toolkit doesn't have this problem.
I run the process under my user's systemd instance, rather than under the PID 1 systemd instance. I like keeping things separate.