I personally don't need the approver_user_id saved in my database, so I just came up with this code to remove it:
/**
* Remove Peter's Collaboration Emails approver_user_id
*
*/
add_filter( 'transition_post_status', 'ac_delete_approver_user_id', 11, 3 );
function ac_delete_approver_user_id( $new_status, $old_status, $post ) {
if ( ( 'pending' == $old_status && 'future' == $new_status ) || ( 'pending' == $old_status && 'publish' == $new_status ) ) {
delete_post_meta( $post->ID, 'approver_user_id' );
}
}It's untested at the moment, but should work. Just throwing it out there incase anyone else doesn't want approver_user_id in their postmeta tables either.
http://wordpress.org/extend/plugins/peters-collaboration-e-mails/
