This makes sense, will do..OK Pete, take a breath.
That last pic is helpful, because it shows how much distance there is between the front and surround speakers. That creates a big empty space, which I suggest filling. That Dolby page is a great guideline, but you need to adapt it to your environment. So, even though in an ideal room with 5.1, you would add speakers almost directly overhead for 5.1.2, I suggest putting the Elevation speakers further forward than "ideal" to help fill in that gap. I'd be inclined to put them on the front side of the vaulted ceiling. As in, right at the opposite side of the peak, and aimed toward the sitting area.
In other words, we already established that your surround speakers are further back than ideal, so I suggest putting the Atmos further forward than ideal to compensate. The goal is to basically fill the room with sound, rather than having all the sound come from the two extreme sides of the room.