emacsclient -nc only creates a new client frame to the default emacs server
-a "" automatically starts the server if it is not already running
-s {socket} tries to connect to {socket} server

Combining these options either connects/starts/restarts to a "default" socket (with win+enter and default for editing files), or
connects/starts/restarts to a named socket.
This makes running emacs through a systemd service not necessary anymore, and restarting a crashed emacs automatic.
An emacs server instance can be shut down with save-buffers-kill-emacs.

The accompanying rofi script displays the existing server sockets and enables running a new instance by entering a new name.