The soundstage illusion is complex.
Move your speakers far apart, point them towards you, and the soundstage appears like a hologram between them.
Put them closer together, toe them towards your ears only slightly, and now the soundstage extends beyond the outer edges of the speakers.
When we're setting up a system it's important to first determine which of these two soundstage models you prefer: stuck between the two speakers or extending beyond them.
Both are valid, both give great results, both work.
But one must choose.
For my systems, I prefer the model where the soundstage extends beyond the speaker's outer edges. This is a fairly simple setup that places the speakers as far apart as they are from the listener to form an equilateral triangle.
To get the most effective illusion from this method the room typically benefits from diffusion behind the speaker.
What works best in your system?