A WordPress mu-plugin to disable visual editing of the homepage and only allow text editing

don't-break-my-homepage.php

<?php
/**
 * Don't break my homepage mu-plugin
 * 
 */
add_filter('user_can_richedit', function ($can) {
    global $post;

    if ($post_ID === (int) get_option('page_on_front')) {
        return false;
    }

    return $can;
});