@ddavis The MAC address is still used as unique identifier by FOG as being the most reliable. Changing that would mean working with the code. Feel free to work on this considering all the things mentioned on github: https://github.com/FOGProject/fogproject/issues/198
The question is what your goal is in the end. Should those devices be imaged and then handed out and never some back? Or do they stay in your network and re-imaged from time to time? If so which kind of network connection will they use in the future?
There are two other routes you can look into:
Register the device with the the USB adapters MAC address and let it do the imaging. Rename the host manually or by OOBE. Install the fog-client service and enable that after deployment so it will automatically register other MAC addresses like wireless, approve those. Some USB adapters have the capability to pass-through the MAC address. This feature allows the MAC address of the native ethernet network device on the system to be used for imaging. Depends on the hardware you have.