Interesting question!  I have long been fascinated with binaural recordings, especially when using headphones to listen to playback.
 
Most of us have two ears, and the 3D sound world around us is experienced by the cues our brain perceives in the slight difference in timing that a sound arrives at each ear.  We can usually tell the direction that a sound originated, whether it was front, back, left, right, near, far, or somewhere in between.
 
The binaural recording only requires a two channel microphone setup, with the mics spaced about the width of a human head, about the same distance apart that our ears are.  One example would be to situate the mics on a mannequin head for realism.
 
It is amazing how real the "illusion" of a stereo field is using this method.  The first time I heard an insect buzzing around my head in the headphones, I was ready to swat it down, because it sounded that real!
 
The free plugin by Auburn Sounds, Panagement (binaural panner), will let you set a channel in your mix anywhere in the stereo space.  Set up a couple tracks in a mix with this plugin and try moving them around.  >https://www.auburnsounds.com/products/Panagement.html

Not sure if this relates to the original subject, but this panning related plugin looks intriguing...
https://www.uaudio.com/ua...cyclosonic-panner.html

I think the idea of stereo spread is even more of an illusion than people think. I can't find the link now, but a while ago I read an article by some audio boffin in which he outlined experiments he did in which he got people to place sounds in the stereo field and then follow them as they panned. I can't remember the exact details, but it turns out that the idea of things moving smoothly in space across the field is largely bogus, and instead they tend to jump between a small number of fixed positions. So when you're fine tuning your pan pots by very small amounts, it doesn't really make any difference in the perceived position. I have to admit, when I hear people talk about panning their snare or hats like 3% left or right to "make room" for the kick and the vocal, I do feel like they're kidding themselves. Personally I only use about 2 or 3 different pan positions on each side in my mixes. I like the sound of LCR mixes as well, they always sound really solid to me. 

sharke
I think the idea of stereo spread is even more of an illusion than people think. I can't find the link now, but a while ago I read an article by some audio boffin in which he outlined experiments he did in which he got people to place sounds in the stereo field and then follow them as they panned. I can't remember the exact details, but it turns out that the idea of things moving smoothly in space across the field is largely bogus, and instead they tend to jump between a small number of fixed positions. So when you're fine tuning your pan pots by very small amounts, it doesn't really make any difference in the perceived position. I have to admit, when I hear people talk about panning their snare or hats like 3% left or right to "make room" for the kick and the vocal, I do feel like they're kidding themselves. Personally I only use about 2 or 3 different pan positions on each side in my mixes. I like the sound of LCR mixes as well, they always sound really solid to me. 

 
Haha, if you do find that article sharke, definitely link it here! I typically don't use more than about 7 - 9 positions - center, plus roughly  quarter on each side. 
That article is definitely something I'd like to check out, maybe I'll search for it and see if I can find it

sharke
...panning their snare or hats like 3% left or right to "make room" for the kick and the vocal, I do feel like they're kidding themselves. Personally I only use about 2 or 3 different pan positions on each side in my mixes. I like the sound of LCR mixes as well, they always sound really solid to me.

 
It makes more of a difference with headphones though. Through headphones I can usually tell if one of the instruments is slightly off-centre and doesn't quite line up with other instruments.