Hi Sam,
The dependency function has been improved from 4.1 so that you can now have a dependency set either per device, or you can set it for a group or a gateway and all devices below will inherit the settings. This is good if you have a dependency on a particular router for example, and if it doesn't respond, you don't want the other devices on the same gateway sending alarms.
In your case though, you might want to combine the dependency monitor per device (<Device>->Edit->Advanced->Device dependency settings) with a maintenance schedule. Schedules are difficult to adjust though since not everyone works from 9 to 5 ;)