I think this would only be possible if you have Process Manager. You could create a workflow that would allow you to monitor the database and create or deploy a task when a new device gets added.
Without Process Manager I believe your way of doing it is about as quick of a turnaround as you can get.
You may be able to complete this if you use provisioning during your imaging process.
One thing you may be able to do is run policy.sync.exe
A couple possible methods:
manually run it
make it one of your last lines in the sysprep
add it to the registry run once
or change your policy time to 15 minutes in the agent config