How to create milestone/Trigger if helpdesk ticket is unassigned or new status for 8 hours?

Summary:

We have a requirement where, if any Helpdesk ticket remains in New status for more than 8 hours, a milestone should be triggered.

Currently, we already have milestones that trigger based on specific queues. However, this new milestone must trigger across all queues, as long as the ticket stays in New status for the defined duration.

I am unsure whether this should be handled by creating two separate Standard Coverages or if it can be accommodated within a single coverage setup. Requesting guidance on the correct approach.