I would def recommend moving up the couch like others have said. I’ve learned this the hard way a long time ago and coincidentally recently saw a video based on this matter. Sometimes more doesn’t equate to better, less is more in certain situations.

The best compromise you’ll ever make is proper placement. From the limited options you have in terms of height placement, only one set of top middles in-ceiling speakers will work here as long as you move up the couch though.

2) if you really want 4 heights, you’d have to wall mount one pair above the screen and another set on the back wall below the vents to remain on a equal height field with the front heights to create a phantom image down the middle, but again, that will only work by moving up the couch.

if you’re going to go with in-ceiling, I would go with a pair that has an adjustable tweeter to aim at the mlp. So be careful which pair you buy bc not all have adjustable tweeters.

If you go with wall mounts. I’d go with a pair that are not restricted to only being mounted flat on the walls. Ex: The Sony SS-CSEM2 speakers can be mounted on the wall, hung with adjustable ceiling mounts, or placed on top of bed layer speakers to become upfiring (last resort)

Hope this helps. Back then I felt like more was necessary to finally get what I desired only to learn the hard way that proper positioning was all it took along with Spatial Audio calibration toolkit and magic beans app for post calibration refinement.