Found the documentation on using prefill for Filedrops which is incredibly helpful. One use case I'd like to request is the same functionality for Secure Messages. One of our use cases for our team is to send messages and include the subject line of an existing Gmail thread with "Re:" at the front so Gmail threads the Filedrop email along with it. Instead of copying / pasting the To, CC, and Subject, I'd like to create a Gmail add-on that includes a button within Gmail that would open the Secure Message page and prefill those details so you can just type the message, upload the file and send. Thanks!