Multiple Post Thumbnails doesn't work with Post Thumbnail Editor about multi-post-thumbnails

[chrisscott]

@dorotheenyc I just added a new release which adds a filter (props to @gglnx for the initial PR) that can be used for this. I've only lightly tested with Post Thumbnail Editor, but if you update to that version (1.6.2) and add something like the following to your theme's functions.php, replacing [post type] and [mpt id] with the post_type and id array values you used when instantiating the MultiPostThumbnails class:

add_filter( '[post type]_[mpt id]_admin_post_thumbnail_html', 'my_pte_admin_post_thumbnail_html', 10, 3 );

function my_pte_admin_post_thumbnail_html( $content, $post_id, $thumbnail_id ){
    pte_add_thickbox();

    if ( $thumbnail_id == null )
        return $content;

    return $content .= '<p id="pte-link" class="hide-if-no-js"><a class="thickbox" href="' 
        . pte_url( $thumbnail_id, true )
        . '">' 
        . esc_html__( 'Post Thumbnail Editor', PTE_DOMAIN ) 
        . '</a></p>';
}

Note you'll need to use the link above (or git) to download version 1.6.2 since I haven't pushed this to wordpress.org yet.