Observer to block qty update in the minicart based on a condition

Here we can implement a observer to block minicart to update qty based on condition firing a event before
<event name="checkout_cart_update_items_before">

Observer code:-

    public function execute(\Magento\Framework\Event\Observer $observer)
    {
        $writer = new \Zend_Log_Writer_Stream(BP . '/var/log/Update item.log');
        $logger = new \Zend_Log();
        $logger->addWriter($writer);
        $quote = $this->checkoutSession->getQuote();
        $request=$this->cart->getQuote()->getRequestQuoteId();
        $logger->info($request);
        if($request>0){
            $logger->info($request);
            exit;
        }
    }