It would be ideal if notifications would automatically clear when their trigger condition is no longer true, and a notification could be sent that the condition no longer exists (this could all be optional).
For example, if a trigger condition is to fire off an elevated alert when disk space is below 10%, it should automatically clear the notification when that condition no longer exists (ie. free disk space increased to greater than 10%).
This is something that would be extremely beneficial for dashboards. Right now, if an alert exists and is dealt with, the dashboard application still shows the elevated alert with the icon next to the system not green, and the only way to clear it is to interact with the dashboard manually. This is not ideal for a dedicated machine that displays the dashboard in an office, for example.