I currently played a lot with QS8 speakers placement and I find your configuration to be wrong. Don't know if you're willing to try something. Keep your couch at the same distance but center it in your room to have the same distance on each side.
Move them 18" each in front of your back couch
I'm not suggesting that you move the speakers permanently, put them temporary on something to try out.
see the picture, when I listen to a movie, I move the couch beside the lamp near the wall. Between the side QS8 and the back QS8. I could live hapilly without the ones in the back but the ones on the side are really in the sweet spot.
Since you room is dedicated to your home theater, I would suggest moving your couches. Put your couches one in front of the other instead of having one of the side. Build a step for the one in the back. This way you would have a configuration exactly like a real theater
Dolby and Axiom both recommended placement of 90 - 110* angle from you, while looking directly at the screen. The QS8 manual states placing them beside or slightly behind and a foot to five feet above your ears is ideal. The picture may be deceiving, but they are about 8" behind my head while seated. It is also not necessary to have them equidistant from the listener, as the receiver and Audyssey take care of delay and level settings, to have the sound arrive to you from each speaker at the exact same time. You can have one 12" away, and another 10', and you will be able to match them with a decent receiver. Of course not every seating position will be ideal, but you set it up for the main position and go from there. Audyssey helps a lot, along with an SPL meter.
I only live here with myself and my wife, the loveseat is really just left over from our old place and we always sit in the larger couch. I did not really consider the loveseat at all when I setup the room audio - wise. If I wanted to go the actual theatre route I would have built a riser and bought theatre style seating as well. I prefer to be able to lie down from time to time so I stuck with the couches.
The only reason I would ever move them forward was if there were two rows of seats, I would move them slightly forward, about 12" and put some more in the back and run 7.1. This room is small enough however that I don't think that is necessary, it sounds fantastic.