Hi cziko,
Thank you for your review.
Regarding your comment: the plugin is unlikely to conflict with other plugins.
Above the fold optimization is a complex and error prone optimization with many different options for ‘fine tuning’ to a perfect result.
The plugin is not intended as a simple ‘on/off’ plugin. It is intended as a toold for optimization professionals and advanced WordPress users.
Did you try different options within the plugin and did you set the Critical CSS, or did you simply install it and view the result?
I am willing to test the RoyalSlider plugin to see if there is a conflict but it is a paid plugin.
The plugin has been improved greatly in the past months. v2.5.0
has several new features such as conditional critical CSS and a Critical CSS quality tester to compare the critical CSS with the full CSS. This last feature will enable you to see if the critical CSS has been configured correctly.
If you are interested to give the plugin another try, I am willing to take a look at your website to see if there is a configuration problem and what you can do to achieve a Google PageSpeed 100 Score.
[ Signature moderated ]