What I understand is that whenever someone loads our website, the plugin will check if the js and css files requested are availble in jsDelivr, then it will load it from there instead from our server. This makes websites fast.
To make the max files to be loaded from jsDelivr, I used only the free theme and plugins available in wordpress.org. Also I removed the child themes and any customization used in the child theme. By doing this, so far I am seeing remarkable speed improvements using this plugin in various sites. You can check out speed of this site here.
Also check the GTMetrix report here.
Its absolutely simple to use, just install the plugin and enable it – thats all – nothing else to configure. Its lightweight and highly useful. Make your website load faster.
I hope that the developer continues to contribute to this plugin.