"Remove above the fold CSS and JavaScript"

You’ll need the pro version of the plugin to do that. The Premium and Optimum settings places the JCH Optimize combined javascript file at the bottom of the page and the Optimum setting adds the defer and async attributes to further prevent javascript render-blocking.

The ‘Optimize CSS Delivery’ setting in Pro Options prevents CSS render-blocking. This setting attempts to extract the critical CSS required to display the section of the page above the fold from the combined file. The rest of the file is then loaded via javascript after the page is rendered.

I’ve added a tutorial to the site to explains how to do this in detail:

https://www.jch-optimize.net/documentation/tutorials/eliminate-render-blocking.html