Comments about toe in are off base. There is no “one size fits all” recommendation regarding soundstage depth and toe in. Not only is this very subjective, but there are many speaker manufacturers that say absolutely no toe in for their design. As a matter of fact, Reference 3a speakers need to fire directly into the room. Anything more than a minute amount of toe in ruins the tonal balance. And this is by design.
So even though soundstage depth may be enhanced by severe toe in, many other parameters may suffer. This is an individual listener and speaker preference.