New-ScriptFileInfo adds all the fields to the scriptfile not just the one you supplied.
New-ScriptFileInfo add all the fields to the scriptfile and not just the ones you supply. Seems like a lot of "clutter" for information you don't need to specify.
Can be reproduced by running the msdn example.
New-ScriptFileInfo -Path "\temp\Temp-Scriptfile.ps1" -Version 1.0 -Author "firstname.lastname@example.org" -Description "My test script file description goes here"
Get-Content -Path "\temp\Temp-Scriptfile.ps1"
Thank you for your feedback, but in this case the cmdlet is doing what we expect.
The goal of New-ScriptFileInfo is to provide developers with the list of metadata items supply that provides value when publishing a script via the PowerShell Gallery, and interacting with it via the PowerShellGet cmdlets. This is consistent with the behavior for New-ModuleManifest.
You may want to save your own subset of the metadata values, and insert it on your own into files.