support ESI (Edge Side Includes) in the Application Gateway and CDN like Vanish or Akamai.
ESI can be a great feature for server side content based integration ( transclude of html fragments ) in a microservice architecture. For more information please read : ( https://gustafnk.github.io/microservice-websites/#integrating-on-content ).
Thank you for your suggestion. We are considering this for inclusion in our roadmap.