Continuing my tests in Articles Good Search I found that the extension is loading the FontAwesome from a CDN but if the user already have FontAwesome (my case) it loads it anyway. So I have 2 FontAwesome files loaded, my local copy and the extension. In my case I only load the icon fonts that I want but the cdn file loads all the fonts.
In my opinion the user should have an option to not load FontAwesome in case it is already loaded by the template. Could be a switcher in the module parameters.
Another option is get rid of the file because is overkill to use a huge file just to load some font icons, specially when you are already using Icon Moon.
Another problem is duplicate CSS styles. For example if I have a filter with one calendar and one calendar range custom field the result tempate loads the exactly same CSS style twice.
In this case I think you should add all the styles to the filter.css and let the user override the css in templates/YOUR_TEMPLATE/css/mod_articles_good_search/filter.css like other modules do. Duplicate content slow down the site. If the user dont need the css rules it can be removed from the override.
Ok, I will try to add such option in the module parameters. Btw, you can already override template files and remove font-awesome loading. Also, you can override the whole template here - templates/your_template/mod_articles_good_search/your-sub-template(Default). and filter.css also located there now, in assets folder.
I already had a module layout with my own overrides wich I removed the cdn link and all the duplicate styles and inline styles and pointed to my own css file. I suggested the module parameter for users that already have FontAwesome but don't know that the module is loading the cdn file and probably don't know how to override it.
Btw, you should update your documentation explaining how to create a layout for the module, because the documentation is only poiting to the search results template override, not the module override.