Hi,
i am afraid i am not really planning adding a feature, but you can add something similar by adding the code below in your theme functions.php file
add_action( "adverts_sh_manage_actions_left", function( $post_id, $baseurl ) {
?>
<form id="mark-as-featured" action="<?php echo esc_attr($baseurl) ?>" method="post" style="display:inline-block">
<input type="hidden" name="advert_renew" value="<?php echo esc_attr( $post_id ) ?>" />
<input type="hidden" name="payments_listing_type" value="123" />
<a href="#" onclick="document.getElementById('mark-as-featured').submit();" class="adverts-manage-action">
<span class="adverts-icon-flash"></span>
Feature Ad $5.00
</a>
</form>
<?php
}, 10, 2 );
The code will show a new button in [adverts_manage] next to each Advert. Clicking the link will take you to the Ad renew page. So technically this is just a shortcut to selected renewal pricing, if user will purchase it his Ad will become featured but also the publication and expiration dates will updated.
The only thing you need to change in the code is the “123” which you should replace with actual ID of the renewal pricing which will feature the Ad.
I suppose this is not exactly what you are looking for but it is the best solution i can offer without a lot of programming.