The spread axel is supposed to be easier to tow by balancing the weight a bit more on the trailer, I don't find it helps.
I do about longevity of the suspension more than tire 'scrubbing' on the corners. I recall once getting out to check clearance on a tight backin and it was scary how twisted out of alignment the axels were. I've heard of people having hanger metal fatigue and other problems with this setup from that, and looking at the time I could see why. I don't think it's an advantage at all, just another possible maintrnce problem.