Simple sample script to test the font load modificaion technique

test-page-script.js

// Test Page: https://keen-northcutt-3190bd.netlify.com/standard-load.html
// Paste below into the WPT Inject Script textarea.
(function(){
    var montserratBold = new FontFace('montserratbold_italic', 'url(fonts/montserrat-bolditalic-webfont.woff2)', {
        display: 'swap', // test the page using 'swap'
        weight: '700'
    });

    document.fonts.add(montserratBold);

    // Wait for the fonts to become ready (optional)
    document.fonts.ready.then(function() {
        for (var allowed of document.fonts) console.dir(allowed);
    });
})();