How to configure
This is our default event which we feel gives the most improvement in the safest way possible. This will wait for the Document Load event which will make that initial render very quick which will improve your user’s experience and your page speed scores.
This is our most aggressive run event which yields the highest page speed improvement but has a slightly higher risk of causing an issue with your site. This will wait one second after the Document Load event. If you choose this event you will want to make sure you test the results to be sure you are getting the outcome you desire.
With these mechanisms, you can configure Script Timing on various parts of your site with various configurations so you can get the most improvement and avoid any possible negative side effects.