FYI, this snippet appears to work to create a post author metafield for use with custom field filtering.
function add_post_author_metafield ( $post_id, $post) {
update_post_meta($post_id, ‘post_author_meta’, get_userdata($post->post_author)->user_nicename);
}
add_action( ‘wp_insert_post’, ‘add_post_author_metafield’, 10, 2 );
Perhaps you’d like to share it with the community, given that it has been a requested feature?
And, while I have your attention here, I sent a few follow-up questions to you regarding my pre-sale inquiry email. I’m sure you’re busy, but I would appreciate if you could take a look and respond. On that note, are tickets the best way to reach you?