title: Can you update items in a transaction in enhanced analytics?
body: <p>I am using the enhanced ecommerce plugin for Google Analytics in my store. </p>
  
  <p>I am using analytics.js to send transaction information in the checkout success page. </p>
  
  <p>After completing the transaction, I want to update some custom metrics associated with products in the transaction which are not available in the checkout success page. </p>
  
  <p>I was wondering if it is possible to do this via the measurement protocol and if so how?</p>
  
  <p>Thanks</p>