I downloaded and installed this plugin and it did absolutely nothing for my site fonts or headers no matter what I did. I tried changing different settings in the plugin settings, nothing. I tried one setting per section, then I tried two settings per section, nothing no matter what I did. I'm glad this plugin apparently works for so many people, but it did zero for me and was as if I never installed it in the first place. For all intents and purposes, it's like an empty installation because it did nothing. So I just deactivated it and deleted it and am moving on to the next plugin.