Is it possible to pass a nav widget in the Wordpress (Sidebar) new $args?

I've spent some time searching, but I haven't really found anything concrete in regards to passing new $args to a navigation widget. I did stumble across "this post here". However, I think the answer is a little overkill for what I'm trying to achieve.

To sum up the linked post it basically goes on to show how you could accomplish what I need, but only if an entirely new widget is created.

---

Specifically, I'm looking to either merge or overwrite the following $args exclusively for a menu widget placed within a Wordpress sidebar;

wp_nav_menu( array $args = array(
   'menu'              => "header-quicklinks",
   'menu_id'           => "quicklinks",
   'theme_location'    => "sidebar-header"
) );

If possible I would like to pass the ID of the widget, in my case nav_menu-6; to the function and have the $args only apply to that menu specifically, this way I can touch up the code to target other menus should I have the requirement.

Currently tinkering with the following;

function widget_nav_args($args){
  $menu = $args['menu'];
  if($menu->term_id === "menu-quick-links") { // < Error: non-object.
     return array_merge( $args, array(
            'menu_class' => 'TESTING', // for testing.
            // More settings here ... 
     ) );
  }
  return $args;
}
add_filter('widget_nav_menu_args', 'widget_nav_args');

Any guidance or resources, I can be guided to would be awesome. Thanks, B.

from Is it possible to pass a nav widget in the Wordpress (Sidebar) new $args?