SOT will never be greater than usage time for a 24 hours period. It is not going to happen I will even go further and say that SOT+background time will never be higher than usage time for a 24 hour period or more.
Try it if you have an iPhone on iOS 9. Run your iPhone like you normally do for a 24 hour period. And then post the screenshots so we can see them. Summarize the screenshots in minutes like I did in my two posts. Go ahead. Prove that SOT will be higher than usage time for a 24 hour period or more. I challenge you and Jamezr to do it.
You stated the reason why you have to wait 24 hours is because it includes the previous 24 hours. This reason is WRONG.
I also explained to you why it balances out after 24 hours. If you use your phone consistently (including lots of app switching from 100%-0% non stop until it almost dies the SOT will be greater than usage. I challenge you to do that.
I reiterate, the reason why it balances out after 24 hours is this...when you are not using the phone, usage time is increasing due to background activity while SOT remains stagnant. Hence after 24 hours, usage will surpass SOT. Now if you use your phone consistently (non stop) then both SOT and usage will be increasing, SOT increasing at a faster rate than usage.