Hi Chris,
Use case is for logging email data to an external CRM. Steps are:
1) User creates email in Gmail compose window and adds some attachments
2) User clicks a button (Log and Send) which pops a modal window and passes composeView data
3) User then performs various actions to categorise the email and add data/CRM links from the composeView data
4) User clicks a button "Send and Log Email"
5) Entry is created in the CRM and the email data is attached to the CRM.
We want to be able to have the ability in step 3) to select attachments to be uploaded to the CRM. We perform a similar process for an inbound email. The user does not always want the attachments to be saved to the CRM so we want to let them choose.