The tail end of the graph is when it hits 11pm and the lines clearly just started to get flat there.
As I said, I got Doze to activate on my A9 for one night only (after a week now), for about 5-6 hours, and the line was definitely flat and consumed only 2% of battery during that time. I did read up a bit on Doze and it does look like the way it works is that it's strictly automatic, and the phone has to be completely idle for 30 min - 1 hour until it kicked in. Well that's very rarely ever going to happen with what I've got going on in the background with the messaging apps.
Just to clarify about the battery problem that I'm personally experiencing with my A9: I don't have a daily use battery crisis. With my typical work day usage, the A9 lasts for ~30 hours until it needs charging. That's with about 2-2.5 hours of screen time on average. My problem is, when my M7 was brand new, for the same usage pattern it lasted for ~40 hours before it needed charging. With the A9 battery being smaller, this just shows that it performs about the same. That's the only thing I don't like about it, and it annoys me.
Everything else is just perfect. I'm liking the screen even more, and finger print to turn on screen *and* unlock is awesome, not even my wife's S6 can do that (how about the Nexuses?). To take the phone out of the pocket, 'thumb' it on the way to unlock and tap it to the machine to pay for something, all in one movement. It's just so damn convenient.
In a bit of an evil twist, I received my Oneplus X invitation this morning. The design looks good and review says it 'feels' premium (glass back though, which is kind of, eh...) as well. But there's no fingerprint reader and no NFC, and no LTE Band 12 or 17. And Oxygen OS... well I gotta read up on that. Clearly overall it's of lower quality than the A9, but it's a mid-range with a mid-range price.