Hello Eric,
yesterday while I was tinkering again to solve the problem, discovered that after removing
session optional pam_ck_connector.so noX11
from the end of /etc/pam.d/system-login file, I was able to start notification-daemon as user classic service.
It was appended there following
this, and because I don't utilize display manager, albeit I was aware of
Note: This specific change at the /etc/pam.d/system-login isn't necessary depending of your .xinitrc declaration file or if you use a display manager.
Now I am wonder ... whether the lesson wasn't learned well or wasn't written well, or the devil is in the detail ... as always is?