I have been looking to do something like that with EditFlow, where a custom status will determine if the post shows up on the homepage via a get_posts() query.
$promoted_posts = get_posts( array( 'post_status' => 'promoted' ) );
That works, but it looks like I'll need to filter the WP Query on the single page so that it respects the 'promoted' status as well as 'publish' status (thus preventing the 404 for promoted posts). Likely in 'pre_get_posts' hook to update 'post_status' to include 'promoted' status. Something like:
add_action( 'pre_get_posts', function( WP_Query $query ){
$query->init();
$query->parse_query( 'post_status=publish,promoted&...' );
return $query;
});
That's not exact code - but hopefully gets the idea across.
As a caveat, I'll point out that doing this seem against the spirit of EditFlow's custom statuses - they seem to be more about the status of a post prior to publishing - at least the examples hint at that ('pitch','needs edit','ready to publish', etc.) and the Publish button still looms on the edit screen, ready to change status to 'publish' at a click. So it feels like this is against the direction of development and practice for EditFlow.
I can achieve the same thing above with a custom taxonomy instead, or possibly using a post meta value. Certainly authors like the idea of toggling the 'status' of the post in order to give it a 'privileged status' - I don't like the idea of filtering every main loop query to include all 'publishable' custom statuses.