Adding existing posts as children to a parent

Using WP Types, I would like to add existing posts as children to parent. Currently, we can only create new children in Parent.

This features has already been asked for twice:
http://wp-types.com/forums/topic/revisiting-add-existing-posts-as-children-to-a-parent/
http://wp-types.com/forums/topic/add-existing-posts-as-children-to-a-parent/

In one of them the support team stated: "our developers are working on it.". This back in January 2013.

I'm having a hard time believing it's taken 18 months to code that feature, since essentially it's about adding UI to an existing API call:
http://wp-types.com/documentation/user-guides/querying-and-displaying-child-posts/
$child_posts = types_child_posts(‘room’);
foreach ($child_posts as $child_post) {
echo $child_post->post_title;
echo $child_post->fields['description'];
}

When will this feature be available?