Using the Divi builder or visual builder on posts was added as a core feature update back in 2017 and Divi continues to evolve and grow with constant updates. In July 2018 a new version release gives you the option of using the Divi builder on your custom post types too.
Where can you use the Divi builder and visual builder?
The Divi builder is expanding its reach and is now available on the standard posts and pages, along with the custom post types such as WooCommerce pages. Currently the Divi builder cannot be used to create templates or dynamic content but this is due to be released soon so check back regularly to see whats new with Divi.