It seems you have done quite a good job placing the speakers in this room optimizing the place of the TV as well as the fireplace while maintaining symmetry. But there is always place for optimization. I suggest you watch this short tutorial for placement tips:
I would also suggest you EQ left and right speakers separately and at more than one mic position for each channel. Some of those dips will disappear in the averaged frequency response and you can focus on the real problems. Magnus has an awesome guide at the top of this page. You can also try a guide I wrote recently if you want to make further phase corrections on top of the REW EQ filters: