Mo, on the soundstage thing, the only thing that comes to mind immediately is if when you moved up to 24" and if you didn't increase the toe-in to compensate for the closer positioning, that you were then inside the axis of the tweeters(or farther inside than before). If so, decreasing the toe-in while at your preferred listening distance might have a similar effect. Another possible adjustment, although you don't have much room to spare, is to separate each AB a few inches wider.

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Enjoy the music, not the equipment.