JSFiddle - React, Tailwind, and code Playground

HTML

<template id="myTemplate">
MyTemplate  
</template>
<div id="myDiv">
MyDIV
</div>
<div>
<span>Template modifications: </span>
<span id="templateCount">0</span>
</div>
<div>
<span>DIV modifications: </span>
<span id="divCount">0</span>
</div>

JavaScript

let divCount = 0;
const divObserver = new MutationObserver(() => {
	document.getElementById('divCount').innerHTML = ++divCount;
});
divObserver.observe(document.getElementById('myDiv'), { subtree: true, childList: true });

let templateCount = 0;
const templateObserver = new MutationObserver(() => {
	document.getElementById('templateCount').innerHTML = ++templateCount;
});
templateObserver.observe(document.getElementById('myTemplate'), { subtree: true, childList: true });


setTimeout(() => document.getElementById('myDiv').innerHTML = 'hoho', 2000);
setTimeout(() => document.getElementById('myTemplate').innerHTML = 'hoho', 2000);