When we press "Save order" button on order edit form, we will stay on order edit form with message "Order saved". But normal drupal way is redirect to entity view page instead of staying on edit form. So will be better to change redirect on view page.
I have found the function that do this redirect:

function commerce_order_ui_order_form_submit($form, &$form_state) {
  // Apply the redirect based on the clicked button.
  if ($form_state['triggering_element']['#value'] == t('Save order', array(), array('context' => 'a drupal commerce order'))) {
    drupal_set_message(t('Order saved.'));

    $form_state['redirect'] = 'admin/commerce/orders/' . $form_state['commerce_order']->order_id . '/edit';
  }
}

and I can'f find the way how to change redirect location via hook from other module, because when I try to do hook_form_alter() and adds new submit, it executes before this function, and commerce_order always rewrite my redirect.

Can you change redirect location in module? If not, can you add setting/api for changing it from other modules?