FYI, what I wound up doing is downloading the Fontawesome pro icons and uploaded to my theme. Then I used Symfony\Yaml to parse the categories.yml and icons.yml to build an array of icons.

/*
 * Add font with icons to Getwid plugin.
 * Use this code in functions.php or custom plugin.
 */

// add hook
add_action( 'getwid/icons-manager/init', 'my_theme_getwid_add_custom_icons' );

function my_theme_getwid_add_custom_icons( $manager ) {

	// register new font
	$custom_icons = [
		// load icons list for visual editor from function
		'icons' => my_theme_custom_icons_list(),
		// or load icons list for visual editor from file
		//'icons' => require( get_template_directory() . '/custom-icons-list.php' ),
		'style' => 'custom-icons',
		'enqueue_callback' => 'my_theme_enqueue_custom_icons_style'
	];

	$manager->registerFont( 'fontawesome-pro', $custom_icons );
}

function my_theme_enqueue_custom_icons_style() {
	//load font css
	wp_enqueue_style( 'fontawesome-pro', get_template_directory_uri() . '/assets/vendor/fontawesome-pro/css/all.min.css' );
}

function my_theme_custom_icons_list() {
	$icons = [];
	$icon_prefix = 'fa-';
	$style_prefixes = [
		'brands' => 'fab',
		'solid' => 'fas',
		'regular' => 'far',
		'light' => 'fal',
		'doutone' => 'fad',
	];
	// This is the directory where I put the fontawesome pro yml files
	$meta_dir = get_template_directory() . '/assets/vendor/fontawesome-pro/metadata';
	// This is where I call Symfony\Yaml which parses the yml to an array.
	$categories = $this->utils->parse_yml( $meta_dir . 'categories.yml' );
	$icons_array = $this->utils->parse_yml( $meta_dir . 'icons.yml' );
	foreach ( $categories as $category ) {
		foreach ( $category['icons'] as $icon ) {
			foreach ( $icons_array[$icon['styles']] as $style ) {
				$icons[$category['label'][] = $style_prefixes[$style] . ' ' . $icon_prefix . $icon;
			}
		}
	}
	return $icons;

}

This will effectively overwrite the icon list for the free version that come with the plugin. However, you will now be loading the pro css and the free css. So I just wp_dequeue_style( ‘fontawesome-free’ ); wp_deregister_style( ‘fontawesome-free’ );

This works pretty well. Future enhancement would be to cache the icons list…