Hi Jon,
There is no such hook currently. You can just comment the line, which initiates the related code:
wp-content/plugins/user-role-editor-pro/pro/includes/classes/user-role-editor-pro.php, line # 35 ( // $this->init_updater(); ) :
protected function __construct() {
$this->lib = URE_Lib_Pro::get_instance('user_role_editor');
add_action('ure_on_activation', array($this, 'execute_once'));
parent::__construct();
add_action('plugins_loaded', array($this, 'load_addons'));
$this->allow_unfiltered_html();
// $this->init_updater();
}
// end of __construct()