There's a good bit of evidence floating around that, except in the case of a HUGE stadium screen, humans can't see the difference between 4k and 8k. Yet they're coming out with TV's, videos and, even worse, video games in 8k! Go figure!
The concept that helped me the most for mixing was to think about everything in 3D (no, not using hallucinogens though those did help! ?).
From the perspective of looking at the "players" directly in front of you; you have panning left to right, frequency up and down, and volume front to back. Making sure that you keep things in their own areas with a good balance kept the mix clean and interesting.
I was right in the middle of getting oscilloscope software calibrated to my gear and learning how to take a mono input source (like a guitar) and make multiple copies for panning when I lost my studio. I really wanted to make that "wall of guitar" sound! Oh well... ?