Coming along very nicely. Are you planning on getting any RT60 readings with all the mineral wool on the wall?
You may want to add some diffusors into the room to give some ambiance to the surround, otherwise it may sound too dead.
Also, looks like you pulled the seating away from the back wall. Good Choice. Again, helps with the surround envelopment.
I like painted screen detached idea from the main wall. very clever. not sure about the led light on the floor on the short wall.
what's your hardware?
Where are the speakers?