"Our very Constitution says quite explicitly they aren't allowed to issue warrants for "unknown" locations."
No, it says what it says. And, it says no such thing.
This is no different than a warrant to search a specific vehicle, independent of the location it might have been driven to. "Place to be searched" doesn't need to mean a physical location, it can mean a specific person or vehicle or computer.
The intent of the restriction is to ensure specificity, so there are no blanket warrants/searches. Allowing warrants for specific computers whose logical, but not physical, location is known doesn't undermine that.