Set Print Scaling in PDF metadata using Node-Exiftool

I'm trying to use Node-exiftool to set the Print dialog Print-Scaling metadata to None.

I don't know how to format the data object to achieve this result, I'm not even sure if it's possible, something like this maybe?:

  ep.writeMetadata(pdfOutput, {
    'Keywords+': [ 'No-Scale', 'PDF' ],
    'Type': {
      'Catalog': {
        'ViewerPreferences' : [
          {
            'PrintScaling': 'None'
          }
        ]
      }
    }
  }, ['overwrite_original']);

This is the pdf metadata result I need:

12 0 obj
<</AcroForm 27 0 R/Metadata 2 0 R/Pages 9 0 R/Type/Catalog/ViewerPreferences<</PrintScaling/None>>>>
endobj

If there's a better tool to do this, I'm all ears too.

thank you!

via BelgoCanadian