Can Autoptimize include an external css file?

Shouldn’t Autoptimize catch all .css files and add it into one?

I’ve an external css typography.com file that i’m enqueue in like so..

wp_register_style('typography_com', '//cloud.typography.com/css/fonts.css');	 
	wp_enqueue_style( 'typography_com');

<link rel='stylesheet' id='typography_com-css'  href='//cloud.typography.com/css/fonts.css' type='text/css' media='all' />

But Autoptimize is not bundling it in with the main Autoptimize css file?