Hi there,
The only way to do this really is to create a custom field for your separate title. Then you’d need to hide the standard title in the WPSP settings and hook the custom field into the list like this:
add_action( 'wpsp_before_content', function() {
$custom_title = get_post_meta( get_the_ID(), '_your_custom_field', true );
if ( $custom_title ) {
echo '<h2>' . $custom_title . '</h2>';
}
} );