In your code I just change this :
if ( apply_filters('wpo_wcpdf_check_owner', WCX_Order::get_prop( $this->order, 'customer_id' ) != get_current_user_id(), $order_ids ) ) {
wp_die( __( 'You do not have sufficient permissions to access this page.', 'wpo_wcpdf' ) );
}
Tell me I you wan the other part.