[bo0mb]

Couldn't you just use createinstallmedia that comes bundled with those Installers instead of using a 3rd party tool?

https://support.apple.com/en-us/HT201372

[callesgg]

it exactly what it does

    sudo /Applications/Install\ macOS\ High\ Sierra.app/Contents/Resources/createinstallmedia --volume "$build_mount"

But it does 2 or 3 more things.

[judge2020]

This is basically a wrapper that handles the mounting process, different mac versions, etc.