Hi Brendan,
When registering the form you can register the callback to be called after post is saved

'update_callback'       => 'buddydev_form_saved_callback',

Now, In the callback, you can redirect as you please.
Here is how the function should look like

/**
 * This gets called when a post is saved/updated in the database
 * after create/edit action handled by BP simple front end post plugin
 *
 * @param int                      $post_id post id.
 * @param boolean                  $is_new is new post.
 * @param BPSimpleBlogPostEditForm $form_object form.
 */
function buddydev_form_saved_callback( $post_id, $is_new, $form_object ) {
// do a redirect here.
}

You get the post id, whether is was a new post or an edit post and the form object.

I hope you can take from there.

Best Regards
Brajesh