Thank you for the response. After putting some time into reading various parts of their site I think I will stick with my current system.

Unfortunately not, each serial is locked to a particular device once it's been activated. The serial cannot be replaced or cleared to be used with new hardware (tablet/phone/headunit etc..), you will need to purchase a new full version serial if you wish to use Desnav on another navigation device. Unfortunately the same applies to lost, damaged or phones/tables that are being replaced, you will not be able to use your serial with your new hardware.
and that's not even the worst part...

The trial serial does not work on all devices especially if it's a Chinese navigation system. Reason being that certain information which should be unique to each device is not and instead, replicated over a wide range of mass produced hardware.
Any company that can't "unbind" a Serial from a Hardware ID is just plain lazy or incompetent.