Problem: The schedule feature completely locks your content 24 hours before the send time which makes it an active hindrance rather than a feature. When you schedule a campaign, it locks all settings, and you can no longer edit the design.

Workaround: Right now, the only way around it is to duplicate the campaign and delete the scheduled one so it doesn't go out.

Solution: Lessen the lock time from 24 hours to maybe 1 or 2 hours. I believe MailChimp allowed you to edit up until the time of sending, as long as you used their "Pause And Edit" button. Or give administrators the option with granular permissions to edit a campaign, for last minute changes to content.