Call Forwarding Options should include an option to NOT forward in some cases or times, such as if user is logged out. The current options always forward, and users may forget to turn forwarding off & on,and prefer caller to page or leave voicemail at tmes rather than always forward.
Thank you for submitting your idea. Enhancements were made in the VCS 3.6 version and its supporting server versions (5.3.3) to enable the use of the DND setting when a user is off campus to prevent messages from being forwarded. This may solve some your issue.