wp-seo-framework-title-inheritance.js

/*
	In Wordpress, using the "The SEO Framework" plugin, we want to break the inheritance
	between the Meta Title and that of OpenGraph/Twitter Title (we also do this for Description but the approach is the same).
  
	While the PHP code appears to work, the 'placeholder' 
	on the field INPUT and TEXTAREA elements still reflects the original behaviors.
  
	This (hacky) code solves for that though a better approach is desired.
	This would break if element IDs were to change in the future.
	You also need to ensure you DO NOT run this code until the element exists.

	Companion PHP code:
	https://gist.github.com/donohoe/a6cfcf5e920e4e3ee29f2bedc1847a53
*/

function() {
	var el = document.getElementById('tsf-inpost-box') || false;
	if (el) {

		var og_title = document.getElementById('autodescription_og_title') || {};
		var og_desc = document.getElementById('autodescription_og_description') || {};
		var tw_title = document.getElementById('autodescription_twitter_title') || {};
		var tw_desc = document.getElementById('autodescription_twitter_description') || {};
		var dekEl = document.querySelector('#row_dek_field textarea') || false;
		var hedEl = document.querySelector('h1.wp-block-post-title') || false;

		setInterval(function(){
			if (dekEl) {
				og_desc.placeholder = dekEl.value;
				tw_desc.placeholder = (og_desc.value.length > 0) ? og_desc.value : dekEl.value;
			}
			if (hedEl) {
				og_title.placeholder = hedEl.innerText;
				tw_title.placeholder = (og_title.value.length > 0) ? og_title.value : hedEl.innerText;
			}
		}, (1000/60))

	} else {
		console.log('Hiding SEO plugin social placeholders');
		document.body.className += ' hide-seo-plugin-placeholders';
	}
}

Instead of using intervals, you may like to use the more advanced https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver.
For performance, I then recommend assigning in config only:

const config = { attributes: true, childList: false, subtree: false };

Perhaps even attributes can be set to false because TSF invokes an onchange event after every update -- though I'm not sure if that also invokes a mutation by default.