Can header & footer be suppressed in PrintPreview->SimplifyPage?
My OS is Ubuntu. And I tried, but couldn't find an option in Cups, although something called a 'PrettyPage' flag seemed to be the closest thing I could find, but I know of no way to use it.
File > Page Setup and Page Setup in the Print Preview window has prefs to change / block the header / footer from being printed -- at least that where that 'control' is on the Windows OS Firefox builds. I'm not familiar with what's available with Cups on Linux nor with 'Pretty Page', though.