Yeah, with your surrounds up as high as they are, I am not sure that you would get much benefit from going to Atmos. I understand that the left surround is the problem.
The closest that I think that you could come to any sort of Atmos install would be a 7.1.2 implimentation with the X.X.2 being 2 speakers in/on the ceiling about half way between the fronts and side surrounds. Even then, the sound of something flying overhead would elevate nicely as it was coming towards you, but by the time it got to those overheads, it would already be mixing/blending with the QS surrounds and starting to diffuse.
It would be better than no overheads there, but I think that the impact would be minimal. If the front left side wall was a bit deeper, I would say you could look at 9.1 with front wides. You could mount them so that they are between the front L/R and side surrounds, and just split the difference in height (half way between the height of the fronts and the side surround). You would have to set your receiver to "upmix" movies to use those wides, but it would give you a "similarly better" but still "different" impact compared to a 7.1.2 Atmos setup. Tough setup for anything more than 7.1, but 7.1 when done right will still sound great, and a LOT better than most people with their large flat-screens and sound bars.
