Reboot computer if no user logged in

I deploy an application with PSADT and SCCM. I would like the computer to reboot after application installs and no user logged in.

The SCCM settings are set to -
Required install
Whether or not user is logged in
Install as system

I use Psexec and ServiceUI to display Show-InstallationRestartPrompt to users if there is a user logged in.

Show-InstallationRestartPrompt does not seem to do anything if no user is logged in. Computer does not reboot. How can I make computer reboot after successful install if no user is logged in?

Show-InstallationRestartPrompt doesnt restart when running silently. At least not yet, in the next update there will be added a parameter that can enable that.