While installing the agent the devices disappear from a scoped technician. This makes it impossible to monitor the devices while they install, and the devices that fail never become visible to the technician.
While the install runs, the value the scope is created with is cleared, and this leaves the device outside of the scope.
UDD uses three hooks to discover the device.
1) MAc Address
2) Device ID
3) IP address
Both the mac address and the device ID are not really good methods of scoping. But, if we have the devices that we want included in the scope separated from those we do not by subnet address, then we can use IP address. This value should remain even when the agent install is running.