I don’t know if you can to this in Avada. The way to do this normally, or how I would do it if I was building a site, would be to have these fields be optional (not required) on posts and then in addition to these fields there would be an acf options page to hold default values. In the template I would see if the post has any values and if not then I would show the values from the options page.
This could be done using an acf/format_value filter in your functions.php file. Your filter would check to see if the field has a value and if it does not then it would return the value from the options page.
