I sit further back than an equilateral triangle, as shown in my Virtual System and I have alternate Toe-In’s for single centered, or two off-center listeners, which requires you to provide the ability to change the angle of toe-in.
https://www.audiogon.com/systems/11516
I sit closer and listen when I clean LPs, more like an equilateral, and the imaging is more like listening to earphones, more intimate, but the sense of space is smaller.
That is true for two of my friends who have essentially equilateral triangles.
Obstructions
Who would have a dining room table and chairs in place like I do? I assure you, all imaging is Phantom, from the unobstructed L and R.
I of course have removed the table and chairs (several times), put down a rug: no difference, even with the Christmas Tree in place, the imaging is terrific. I just promised a friend that we will do that again next time he comes over.
After Easter, we are having 14 at that table, where are the 3 leaves?
you might try this ’behind the listener’ toe-in
My preference is to minimize secondary reflections, i.e. a greater time delay before they get to you. That improves imaging. No wall close behind you helps with that.
My vintage horn tweeters and horn mids are designed for wide lateral dispersion and narrow vertical dispersion. Even so, tweeters angle of dispersion is narrower that mids and bass.
I tilt them back, so the tweeter is aimed slightly up at seated ear level. That also alters the reflections off the floor and ceiling
I toe them in so the narrow highs are directed at the listener, to equalize the power of the frequency range, and alter the angle of reflections off the side walls.