function wpf_product_meta_fields( $fields ) {

    $fields['course_date'] = array( 'label' => 'Course Date', 'type' => 'date', 'group' => 'woocommerce' );

    return $fields;

}

add_filter( 'wpf_meta_fields', 'wpf_product_meta_fields' );

function get_product_data( $order_data, $order ) {

    foreach ( $order->get_items() as $item ) {

        $product_id = $item->get_product_id();

        $meta_value = get_post_meta( $product_id, 'acls-p-course-date-a', true );

        if ( ! empty( $meta_value ) ) {
            $order_data['course_date'] = $meta_value;
        }
    }

    return $order_data;

}
add_filter( 'wpf_woocommerce_customer_data', 'get_product_data', 10, 2 );