Also, carefully scale the room to determine the optimal TV size based on viewing distance. You are showing about six foot wide screen, which is unnecessary for a three seat home theater. With just a three person couch I would get a 65" OLED and move the couch forward. Your best window treatment in this room would be black out drapes.
If you will add a side chair and keep the couch back, consider a projector instead of a TV. Projectors provide an immersive experience that is very cool. 1) Determine primary viewing distance 2) Determine optimal display. Also, don't let Atmos drive your design. Your display and front channels are primary.