What makes speakers produce a 3D image is being symmetrically equidistant and pointed towards the listener. Period.
While precisely balanced speakers are important, not all speakers sound at their best this way.
Quite frankly, some speakers sound better off-axis. A lot of high quality tweeters have resonances which you can tame by toeing the speakers out. Further, if you have a very small room, sometimes crossing the speakers in front of your head reduces side reflections significantly and improves imaging.
Lastly, as some speaker developers have discovered, despite our best intentions, sometimes listening below the tweeter axis is also beneficial.
The final judge is your ears and your circumstances.
Best,
E