For feedback, we keep everything in Figma. All emails, flows, pop-ups and any additional design or copy materials are delivered in a Client File that has view & comment privileges. Once we receive the feedback, we typically are able to implement them within 24-48hrs (depending on the complexity of changes) and then we begin uploading to Klaviyo. We aim to stay 2-4 weeks ahead on emails and scheduling to avoid any last-minute changes, and to push our clients to keep us in the loop on their marketing calendar & initiatives.