I see. I'll consider to add some kind of "use defaults on first start" in future, even in the next version maybe.
But right now, when you create your install script, you can achieve the same result by copying configuration file from your personal installation to the users AppData folder during install. There only one caveeat - configuration folder name depend on Nomad installation path. So if your install script is unattended and always installs Nomad in the same folder, then you can copy "default" user.config during install.
You'll find user.config file and configuration folder name in %nomadcfgdir% environment variable.