@mkummer I’m afraid that for your specific theme and set of plugins, you will need to hire a developer to fix the remaining issues.
For the render blocking font, FVM and all other plugins can only capture it if those files are enqueued properly, via the wordpress hook.
https://www.wpbeginner.com/wp-tutorials/how-to-properly-add-javascripts-and-styles-in-wordpress/
In your specific case, the CSS file is not enqueued, but rather “imported” via the tve_custom_style
inlined code, added probably by one of the Thrive plugins or themes.
https://prntscr.com/lnkwbu
FVM doesn’t capture imports, only files that make use of wordpress hooks and filters.
A developer will remove that import code from the tve_custom_style
inlined code and enqueue the file properly, which will then be available for FVM (and others) to capture it.
You also have a jquery file that is render blocking, however if that wasn’t captured by FVM, it was probably manually added (printed, not enqueued) to the theme or via some other plugin. https://prntscr.com/lnkyvp
Specifically, the ?v=1.400.6 part, tells me this is not the enqueued by the default method on wordpress, because that query string is not part of the core.
If you need to improve your score further, you will need a developer to look at your theme and plugins, and make the necessary adjustments so that it follows the recommended standards on google pagespeed tool, and wordpress api.
Sorry that I cannot help you further on that.