SOT measurement is done from 100% to 0% the screenshot is misleading and shows SOT during a 24hrs period that includes a charge time, meaning SOT before charge + SOT after charge, following that logic you can get up to 17hrs of SOT if you want. Below is how u measure it.
I track my screen time by looking at the last 7 days. I usually do this to track my charging habit. It's not scientifically correct but that's the way I used it. Thanks for sharing and you may want to post your analysis but that's about it.