workfowy-tags.user.js

// ==UserScript==
// @name Restore title to workflowy tags
// @namespace Violentmonkey Scripts
// @match https://workflowy.com/*/*
// @grant none
// ==/UserScript==

let timer = void 0

const update_tags = () => {
  const elems = document.getElementsByClassName('contentTag')
  Array.prototype.map.call(elems, (e) => {
    if ( ! e.class_added) {
      e.class_added = true
      const child = Array.prototype.find.call(e.childNodes, (n) => (n.className == 'contentTagText'))
      if (child) {
        e.className = 'contentTag ' + ('tag-' + child.innerHTML).replace(/[#@]/g, '')
      }
    }
  })
}

const queue_tag_update = () => {
  window.clearTimeout(timer)
  timer = window.setTimeout(update_tags, 300)
}

window.onload = () => {
  queue_tag_update()
  window.addEventListener('keydown', queue_tag_update, { passive: true, capture: true })
  window.addEventListener('click', queue_tag_update, { passive: true, capture: true })
}