Absorption, Diffusion or a combination of it all?

You can reach out to GIK directly and they will do an assessment of your listening environment. GIK has an online form that you fill out and you can include photos of your room. I had tried doing it on my own, by tackling first reflection points. But when the analysis came back one of their techs came back with a detailed analysis and set of recommendations that included some of the things I had and then went further, like a pair of 4A Alphas Series Bass Trap Diffusor/Absorber -- which are amazing! -- that go "on" the front wall, behind the speakers (though not directly behind.)

Anyhow, to me, that is the way to go. Reach out to them and see what an expert says.

@Gordon

Yes, that was my experience. Mike Major was the guy that helped me. I submitted all my stuff. He replied right away that he was stacked up and would need some time to review. (I liked that b/c he set the expectation up front.) He wrote a fairly lengthy set of recommendations and comments. I was impressed.

I wouldn't have posted if I wasn't so pleased.

Maybe you could try again and/or call them.