PS: We've been doing some research on AWS's ENI (Elastic Network Interface). Seems like you can attache and detach these to specific instances. http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html
What's great is then that if the Aware Licence is Tied to a MAC address, then you could potentially use the Same ENI when Upgrading the server (I.e. T2 Medium > T2.Large) without affecting your licence as you would essentially have the same MAC address on the new machine.
This is one of the biggest risk factors for us at the moment in that Should a server crash, or we urgently need to upgrade, and cannot get hold of Vlad, then we are in massive trouble. However if we can figure this out then it won't be necessary to deregister your aware copy and Re-Register on the upgraded machine.
Still trying to figure out if this would work and how, so if anyone else has done this before please chip in. I Will certainly sleep better at night knowing that my current licences and servers are not dependent on Aware's Support Availability when I urgently need it.