Switched to only using $mod_next+0 to exit.

Other implementation is pretty env dependent.

i3/config.simple

@@ -195,24 +195,7 @@ bindsym $mod+Ctrl+r restart
 bindsym $mod_next+l exec i3exit lock
 
 # exit i3 (logs you out of your X session)
-#bindsym $mod+Shift+e exec "i3-nagbar -t warning -m 'You pressed the exit shortcut. Do you really want to exit i3? This will end your X session.' -b 'Yes, exit i3' 'i3-msg exit'"
-
-# Set shut down, restart and locking features
-bindsym $mod+0 mode "$mode_system"
-set $mode_system (l)ock, (e)xit, switch_(u)ser, (s)uspend, (h)ibernate, (r)eboot, (Shift+s)hutdown
-mode "$mode_system" {
-    bindsym l exec --no-startup-id i3exit lock, mode "default"
-    bindsym s exec --no-startup-id i3exit suspend, mode "default"
-    bindsym u exec --no-startup-id i3exit switch_user, mode "default"
-    bindsym e exec --no-startup-id i3exit logout, mode "default"
-    bindsym h exec --no-startup-id i3exit hibernate, mode "default"
-    bindsym r exec --no-startup-id i3exit reboot, mode "default"
-    bindsym Shift+s exec --no-startup-id i3exit shutdown, mode "default"
-
-    # exit system mode: "Enter" or "Escape"
-    bindsym Return mode "default"
-    bindsym Escape mode "default"
-}
+bindsym $mod+0 exec "i3-nagbar -t warning -m 'You pressed the exit shortcut. Do you really want to exit i3? This will end your X session.' -b 'Yes, exit i3' 'i3-msg exit'"
 
 # arrow key resizing without resize mode
 bindsym $mod+$mod_next+Left resize shrink width 100 px or 10 ppt