I guess I'm also interested in whether this could be done. Offhand, I don't know how to do it.
That said, I do not recall ever seeing a file named tty.conf, and after reading your post I rooted around in my old Mandriva 2010 (32 bit) installation as well as in a couple of different OpenSUSE installations that predate systemd. Also, such a file, if it existed, would not be found in /etc/init, /etc/init.d/ or /etc/rc.d/init.d - that would be the wrong place for a .conf file.
I think this will help you:
https://fedoraproject.org/wiki/Systemd# ... erminal.3F