This is with resolution set to 1440P+ and using the default white menu theme, could probably do 10.5 hours+ screen on time, by far the best battery life of any phone I've had and I've had the Mate 10 Pro.
You can try getting around the App Killing by going to:Agreed! Even with the Mate 20 it's fantastic and the first phone that eliminated battery anxiety for me. One thing I do notice though is how agressive EMUI is about killing background apps.
You can try getting around the App Killing by going to:
Settings - Battery - App Launch - and turning Off 'Manage All Automatically'