Best navigation method for nested categories

Is there an efficient (i.e. perch native) method for generating a navigation system from nested categories?

I'm using a for loop to pull the data from the perch_categories array but fear that this is a massively inefficient hack as it pulls all the data even though I only need a couple of fields?

I assume this approach won't benefit from any kind of perch template caching so I could link to a script that writes the output to a file and include that instead, but I would rather use native Perch functionality if it's available.

Does anyone have any recommendations?

    $navlist = perch_categories(array(
        'set'=> 'categories',
        'skip-template' => true
    ));

    $first_parent = true;
    for ($i=0;$i<count($navlist);$i++) {        

        if (strpos($navlist[$i]['catDisplayPath'], '›')===false) { // › not present so parent category
            if (!$first_parent) { echo "</ul>\n</li>\n"; } // only close ul after the first
            $first_parent = false;
            $cat_slug = $navlist[$i]['catSlug'];
            echo '<li><a href="#">'.$navlist[$i]['catTitle']."</a>\n<ul>\n";
        } else {
            echo '<li><a href="/category/'.$cat_slug.'/'.$navlist[$i]['catSlug'].'">'.$navlist[$i]['catTitle']."</a></li>\n";
        }
    }