jazzi
If you alter the CSS, so that the Google font isn't used anywhere, it won't be requested even with the linked stylesheet still in place.
In my forum I have changed the font to Titillium Web by adding the necessary stylesheet via the admin interface (Appearance > Custom Header) and requesting the font via custom CSS (Appearance > Custom Styles). So now I have two linked Google fonts stylesheets:
<head>
...
<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,400,700,600">
...
</head>
<body>
<link rel="stylesheet" href="//fonts.googleapis.com/css?family=Titillium+Web">
...
<body>
Now, let's have a look at the web page test results (go to the Details tab): Two small CSS files from Google are requested, but only one font, the Titillium Web. The Open Sans fonts are not loaded:
...
3: https://fonts.googleapis.com/css?family=Titillium+Web
4: https://fonts.googleapis.com/css?family=Open+Sans:400italic,700italic,400,700,600
...
9: https://fonts.gstatic.com/s/titilliumweb/v6/7XUFZ5tgS-tD6QamInJTcZSnX671uNZIV63UdXh3Mg0.woff2
...
I'm not shure, whether files from fonts.googleapis.com are blocked as well, that might still cause delays, but if only files from fonts.gstatic.com are blocked, then overriding the Google font via custom CSS should solve your problem. It's worth a try:
body {
font-family: 'Arial,sans-serif;
}
