Would diffusion help in this space

Is that just a drop down in the ceiling that I see in the photo of your speakers from head-on?

Yes it is
To answer your other question
I experimented quite a bit with different placements
GIK acoustics also worked with me on the room and placement options

Any other opinions on how to increase depth and soundstaging with my current speaker positioning

Is diffusion the answer ?

Musicfile,

I suggest you ask Bruce or Brian at GIK. I have always heard that diffusion needs a larger space to work, but I'm no expert.

YOu can post a question here and expect a quick reply from someone at GIK or Ethan from RealTraps.

Acoustics Circle

My answer may have been inappropriate due to my misunderstanding. IMHO, great depth of image (pin point imaging) can exist only when you have achieved optimum resolution in equipment, room and set up. (My biggest improvement in depth of image came with boxes with SOTA tweeters).

Diffusion could help your sound if placed on the wall behind your chair. Although I doubt it, it might even help on the side walls as well. So could some deadening materiel. The frequencies that bring depth of image to life are the high frequencies so you can (sorta) replicate the effects of using expensive materiels by simply hanging some heavy materiels on the wall(s) temporarily and see what happens. If you get no change at all in depth of image then you can figure you are barking up the wrong tree.

FWIW. It is hard to fine tune a system over the internet. :-)