“From what I gather by experimentation, Chrome only follows the @page rule if you have Margin set to Default.”
Companies replace handwritten forms with web apps, and then everybody still prints them. The @page rule controls the output until a user touches one setting in Chrome’s print dialog, and then it stops. Setting the page size does not put that paper in the tray either. The page autofills from the database, and getting it onto Letter paper still takes trial and error.