We'll create fresh WordPress site with Defer CSS Addon for BWP Minify installed. You have 20 minutes to test the plugin after that site we'll be deleted.
BWP Minify is a powerful plugin to minify and compact several CSS files into only one.
If the resulting CSS file is too big or large, this addon allows to defer the load of this generated CSS file moving their declaration from header to footer, and put it again using asynchronous javascript and DOM manipulation.
This technique is recommended to use in conjuntion with the “css-above-the-fold” practice, as well introducing early CSS in-page allows proper styling display while the main CSS file is still loading.
There are some options to do the above-the-fold optimization, also we have developed a CSS Above The Fold plugin that reuses the current theme stylesheet extracting chunks of CSS code applying a special markup.
Another plugin that does this solution but providing an administration area to configure it manually is Autoptimize, that allows to define a specific CSS code in a independent way of your theme CSS stylesheet.