phab-comment-box.js

// ==UserScript==
// @name        Phabricator Move Comment Box
// @version 1
// @match       https://developer.blender.org/D*
// @description Move the phabricator comment form to a more reasonable location
// ==/UserScript==

// Util for inserting after nodes
function insertAfter(newNode, existingNode) {
    existingNode.parentNode.insertBefore(newNode, existingNode.nextSibling);
}

let commentBox = document.querySelector('[data-sigil="phui-comment-form"]');
let preview = document.querySelector('[class="phui-comment-preview-view"]');

let toc = document.querySelector('[name="toc"]');

if (commentBox && preview && toc) {
  commentBox.remove();
  preview.remove();
  
  let navMarker = toc.previousSibling;
  navMarker.parentNode.insertBefore(commentBox, navMarker);
  
  insertAfter(preview, commentBox);  
}