the ability to sync to enterprise project management calendars such as Wrike or MS Project
I think the ability to sync with project management calendars such as Wrike or MS Project would be invaluable to large organizations and encourage adoption and use of your app.
These project management applications are narrow-minded and require users to keep separate calendars for projects that do not sync with the email and calendars we ALL use to actually collaborate and do work in - namely MS Outlook.