The VM option `UseNotificationThread` is deprecated. It will be obsoleted and then removed in future releases. When debugging notifications were switched from being sent by the hidden "Service Thread" to the non-hidden "Notification Thread", this option was provided (defaulting to true) so that it could be disabled if any problems arose using the "Notification Thread". As no problems have been reported, the "Notification Thread" will become the only way that notifications are sent in the future, and the option will no longer be available.