Runit doesn't have a concept of instantiated services. But it's not a big problem as there aren't that many instantiated services and you will always know that all services started on boot are in /etc/service, while with instantiated services you need wildcards to find them if you don't know their exact name(systemctl status "*@*").
You probably won't notice anyway, as eg. all getty@tty1-6/run scripts point to the same getty@/run script, with each service having their own conf file.
