A: Hey there,

Thanks for the kind words. In answer to your question, Microthemer only manages the CSS it generates. It doesn't concern itself with general optimisation of theme and other plugin CSS / JS assets. LightSpeed cache (free) or WP Rocket (premium) handle those tasks well. Microthemer just makes sure it applies it's own CSS in the most lightweight way possible, as recommended by web.dev:

https://web.dev/defer-non-critical-css/

To achieve this, Microthemer separates CSS for elements that will appear off-screen (below the fold) when the page first loads, so the styles can be loaded asynchronously. This means they don't block the rendering of other content, like CSS for above the fold elements, and HTML text and images. This makes the page load faster for the user.

There is no real consensus about where the pixel threshold for "below the fold" should be. Some say 600px or 900px is a reasonable benchmark. Microthemer opts for 1440px, to include all screens apart from really big ones (e.g. 2560px). That's to be on the safe side. But it's a configurable threshold. I've written about this in more detail on my blog article that introduced version 7.2:

https://themeover.com/microthemer-7-2-released/

On the UI side, Microthemer places selectors into a separate folder for elements above or below the fold threshold. You can always customize how a folder loads on the site. You might find the following videos useful:

* https://themeover.com/automatic-page-speed-optimisation/
* https://themeover.com/load-wordpress-css-on-specific-pages/

I hope that helps. Please let me know if you have any more questions.

Cheers,
Sebastian