observations and reports

The ATSServer process sometimes stalls the system upon login, and there is nothing you can do to kill it at this point except killing it by ssh from another machine. But what to do when there is no other machine you can use to login from? It gets even worse if you activate/deactive a lot of fonts during your session. 

The solution I found, which fits my needs, was to create a LogoutHook, which kills ATSServer on logout.

1. Create a simple sh script:

   #!/bin/sh
   killall ATSServer
   

   Save it in a convenient place, like /usr/local/bin, and name it killATSServer.sh Then make it executable via sudo chmod +x killATSServer.sh.
   
2. Make it a LogoutHook by entering the following command:

   sudo defaults write com.apple.loginwindow \
   LogoutHook /usr/local/bin/killATSServer.sh