Add section to custom menu panel

I have made a custom menu for the nav menu page to add post type archives just like posts/pages etc. I don’t think it’s possible to make it change the url on siteurl change. You could add the url as /slug/ instead of http://url.com/slug/, but that won’t work with WordPress in a folder.

function add_post_types_nav_menu() {
    add_meta_box('post_types_meta_box', __( 'Post type archives' ), 'render_add_post_types_nav_menu', 'nav-menus', 'side', 'default' );
}
add_action('admin_init', 'add_post_types_nav_menu');

function render_add_post_types_nav_menu() {
    $post_types = get_post_types(array('public' => true, '_builtin' => false), 'objects', 'and');
    ?>
    <div id="posttype-archive" class="posttypediv">
        <ul class="posttype-tabs add-menu-item-tabs">
            <li class="tabs"><?php _e( 'Post types' ); ?></li>
        </ul>
        <div class="tabs-panel tabs-panel-active">
            <ul class="categorychecklist form-no-clear">
            <?php $i = 0; foreach ($post_types  as $post_type ) : $i++; ?>
                <li>
                    <label class="menu-item-title"><input type="checkbox" class="menu-item-checkbox" name="menu-item[-<?php echo $i; ?>][menu-item-object-id]" value="<?php echo $post_type->name; ?>"> <?php echo $post_type->labels->name; ?></label>
                    <input type="hidden" class="menu-item-title" name="menu-item[-<?php echo $i; ?>][menu-item-title]" value="<?php echo $post_type->labels->name; ?>">
                    <input type="hidden" class="menu-item-url" name="menu-item[-<?php echo $i; ?>][menu-item-url]" value="<?php echo get_post_type_archive_link($post_type->name); ?>">
                    <input type="hidden" value="custom" name="menu-item[-<?php echo $i; ?>][menu-item-type]">
                </li>
            <?php endforeach; ?>
            </ul>
        </div>
        <p class="button-controls">
            <span class="list-controls">
                <a href="http://wordpress.stackexchange.com/wp-admin/nav-menus.php?page-tab=all&amp;selectall=1#posttype-archive" class="select-all">Select All</a>
            </span>

            <span class="add-to-menu">
                <input type="submit" class="button-secondary submit-add-to-menu right" value="Add to Menu" name="add-post-type-menu-item" id="submit-posttype-archive">
                <span class="spinner"></span>
            </span>
        </p>
    </div>
    <?php
}