Turbolinks simply replaces entire `body` in all cases. Components outside `body` sounds strange. So I think it's okay. For DOM nodes created by script on the fly, they are not mounted by react_ujs. While jquery_ujs uses `$.live` so it can handle dynamically created nodes. However, monitoring DOM changes is expensive. It's probably fine to let the user manually call `React.renderComponent` on dynamically created nodes.