How to deal with JS loading optimization in Wordpress?

Question

WordPress

I'm trying to learn how to optimize. Goes with a big creak. there is little information, they rarely answer, they advise hiring someone ....
So, the resource https://gtmetrix.com writes the first item in the necessary to optimize the download speed:
639.5KiB of JavaScript is parsed during initial page load. Defer parsing JavaScript to reduce blocking of page rendering.
and then the list:

https://dl.dropboxusercontent.com/u/19954007/asks/... I
take for example, one of the files listed in the list - ..../TweenMax.min.js
I climb into the topic, I find where it connects, I see:

wp_register_script('greensock', bla-bla....TweenMax.min.js', array('greensock_easing'), null, true);

i.e. - php wp_register_script( $handle, $src, $deps, $ver, $in_footer ); we see that the script is connected in the future
, it does not interfere with the loading and rendering of the page.
Explain what else can be done here with this script? I thought that all "optimization analyzers" sleep and see JS in the footer. But is everything ok here? And the rest mentioned https://gtmetrix.com are also in the FOOTHER!
Who is to blame and what to do?
Thank you.

Answer 1

It seems to me that the point here is not where the scripts are, but the fact that they are kilometer-long (hello to twitter a couple of years ago). Still, 639.5KiB is a lot, especially for phones / tablets and mobile Internet. Perhaps some of them can be connected on demand, and not on all pages. Call some of them with scripts (use the same jQuery.getScript, for example).

Answer 2

Answer: async, defer . More details here .