How to get next and previous post links, alphabetically by title, across post types, in a shortcode

I need next and previous post links in a single post page using a “page-builder” type of CMS—specifically the DIVI theme by Elegant Themes. So, I need the links to be able to appear using Shortcodes, as the controls in the template, along with a lot of the default template stuff, are hidden when you use the page builder. AND, my client needs to be able to manipulate where in the page layout the next/previous post controls appear, depending on the post type, as it’s a portfolio site and “sculptures” get treated with a different layout than “paintings”, if that makes sense.