[Observium] Device availability - possible feature request?

Hi

For the purposes of alerting, is availability a a metric that can be used, and if not is it possible to add somthing where we could create an alert

i.e.

Type device device_availabilty le 99.5% Device Match * Entity Match * Delay 1

The issue I see is that the duration or scope is a defining factor, i.e availability over X days or X months etc