I read somewhere that having a tv between your speakers is no worse than drywall or windows or wood. I’ve tried absorption covering the tv but it just sounded like the center image became diffuse, flat and dull. Uncovered sounds lively and open and no smearing of the image.
I have a bunch of GIK alpha panels and corner traps and some commercial wood diffuser. I’ve been moving them around the room for a few years and found that, in my room, a 2’ X 2’ diffuser behind each speaker (ear level) and absorption panels in the rear (of the room) and in a (wet) bar area of the room works best. The wet bar makes my room a fat “L” shape. I had a nasty bump between 80hz and 125hz. Loading up the bar area with absorption panels + corner traps solved the problem. Any absorption on the front wall sucks the life out of my Maggies and too much diffusion (front wall) makes it sound phasey and weird. I experimented with placement until I found what sounds “right” to my ears. BTW, my GIK Alpha panels are equipped with scatter plates and the corner traps have range limiter facias.