async and defer

Hi there,

according to google develops advise, we should use the async and defer for our JS and Styles
https://developers.google.com/speed/pagespeed/insights/

Is there any way possible to do that when calling under the controller files?

The version i'm using is 2.3.0.3

Many thanks

i thing i've found my self an answer to that:

$this->document->addScript('xxx/jquery.hoverIntent.min.js', 'header', false, true);

where 2nd is location, 3rd is defer and 4th is async... is this still correct for the last version?