Q. How is the Nano server configuration applied to the VHD it creates as I don't see an unattend.xml answer file created?
A. In TP4 an unattend.xml file was created and placed in the VHD file generated by the build Nano PowerShell that contained the instance configuration. This file is no longer found in the VHD created with TP5. It works by using the unattend application feature of DISM that enables the offline application of an unattend answer file to an image directly without requiring the unattend.xml to be passed during the specialize phase. If you look at the Nano Server image generator script you will see the DISM line that uses /Apply-Unattend parameter which is how the configuration is applied. The great thing about this approach is it then allows you to add your own unattend.xml for additional configurations required during specialization.