Change log
Enhancement: Update delay JS script to catch click events before the scripts are loaded.
Enhancement: Add the delay JS script to the page after the meta charset if it's present.
Enhancement: Remove the clear cache notice after using clear used CSS since it also clears the cache.
Bugfix: Prevent a possible error on WooCommerce product pages with delay JS enabled.
Bugfix: Prevent a possible PHP notice in some cases when using remove unused CSS.
3rd party compatibility: Improve delay JS compatibility with a number of scripts.
Source: Github