Add a button that schedules a meeting with everyone that is on the email. It would be on the three-dot dropdown menu along with "Forward" and "Forward as a new conversation" - something like "Schedule meeting" - click that would pop open the calendar with everyone in the email already pre-populated (TO: would be required, and CC: would be optional).
Current functionality that exists in MSFT Outlook (one of the only features I miss when using Front).