More nuanced maintenance windows

It would be nice if the maintenance windows could be enhanced to support individual items/triggers or applications.

Sometimes specific maintenance only applies on certain services/applications. Putting a host in maintenance mode would result in not getting notifications for services that are not in maintenance.

For instance, maintenance is being done on MySQL but an issue with diskspace arises. If the maintenance window is active, no notifications would go out even though this was not the focus for the maintenance.