I use the default settings of ezjscore, with a brand new ezp 4.4
With default settings which is disabled CDN.

I have installed ezfind that uses autocomplete and new nice features,

However on my website, ezjscore loads external .js from the CDN, instead of getting them locally (which I prefer).
Here are the files retrieved on yahoo:

http://yui.yahooapis.com/2in3.1/2...i2-connection/yui2-connection-min.js
http://yui.yahooapis.com/2in3.1/2...utocomplete/yui2-autocomplete-min.js
http://yui.yahooapis.com/2in3.1/2...m/yui2-skin-sam-autocomplete-min.css
http://yui.yahooapis.com/2in3.1/2.8.0/build/yui2-yahoo/yui2-yahoo-min.js
http://yui.yahooapis.com/2in3.1/2.8.0/build/yui2-event/yui2-event-min.js
http://yui.yahooapis.com/2in3.1/2.8.0/build/yui2-dom/yui2-dom-min.js
http://yui.yahooapis.com/2in3.1/2...i2-datasource/yui2-datasource-min.js

However i can see some of these js files in extension/ezjscore/design/standard/lib/yui/2.8.1/build:
extension/ezjscore/design/standard/lib/yui/2.8.1/build/connection/connection-min.js
extension/ezjscore/design/standard/lib/yui/2.8.1/build/autocomplete/autocomplete-min.js
etc...

the files have different names, but I really think they can be used instead of files on the CDN

=> maybe it comes from the fact ezjscore uses 2.8.1, but loader everywhere contains 2.8.0 ? (however a symlink from 2.8.0 to 2.8.1 does nothing)

=> maybe ezfind has to change something ?
For your interest, ezfind, it loads yui2-connection, this way:
YUI(YUI3_config).use('yui2-connection', 'yui2-autocomplete', function (Y) {
YAHOO = Y.YUI2;
initAutosuggest();
});

Maybe ezfind should load this in another way in order to use the bundled extension/ezjscore/design/standard/lib/yui/2.8.1/build/autocomplete/autocomplete-min.js ?

By using locale .js file for yahoo, ezjscore will be able to minify everything, which is an interesting optimization...