Is MutationObserver called for each DOM node insert or is the call batched?

Question

I am trying to delete some scripts on page load via the use of TamperMonkey.

I am using MutationObserver to figure out when a script event loads and if so delete it and place my script on it.

// ==UserScript==
// @name         Block Scripts Before Execution
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Run a script before any other scripts on the page
// @author       You
// @match        *://*/*
// @grant        none
// @run-at       document-start
// ==/UserScript==

(function() {
    'use strict';

    // Use MutationObserver to watch for script elements being added to the DOM
    const observer = new MutationObserver((mutationsList, observer) => {
        for (let mutation of mutationsList) {
            if (mutation.type === 'childList') {
                for (let node of mutation.addedNodes) {
                    if (node.tagName === 'SCRIPT') {
                        console.log('Blocked script:', node.src || 'inline script');
                        node.remove(); // Block the script by removing it
                    }
                }
            }
        }
    });

    // Start observing the DOM for new script tags
    observer.observe(document.head, {
        childList: true,
        subtree: true
    });

})();

Now my question is that will the callback be called for each and every DOM node insertion ?

Or will it be batched and then called ?

Because it is imperative that I replace the script before the window.DOMContentLoaded is fired.