Very nice set up!!
I have already done all room acoustics.
Well, then I almost have nothing else to say!! :D
I don’t know that you can get better, but, as far as the hobby is concerned, I might suggest a couple of directions that would be big changes vs. just attempting to get better multi-way speakers. For the sake of the hobby, do something really different, like investigate line arrays or horns.
If you just kind of shuffle multi-way speakers, you may get better, but will it be enough of a change or will it just be a little different and possibly more expensive?
Let me know which way you end up going.
Sorry, my previous post had you adding subs, which you already have! :) Assuming they are well integrated, and EQ’d you are all set there. Along with room acoustics, the only other thing I might suggest is plug those ports and re-calibrate the subs.
Best,
Erik