Now let's see the battery life capabilities with one watch for sleep tracking and the other for everything else. SE and AU Watch combo. : r/ AppleWatch
Sleep Tracking in Apple Watch Might Be Useless Unless Battery Life Is Improved - Rapid Repair
watchOS 7: Hands-on with native Apple Watch sleep tracking - 9to5Mac
Apple Executives Discuss watchOS 9's New Health Features Like AFib History and Tracking Your Sleep Stages - MacRumors