After speaking with several NSX alignment experts, I've heard mixed things about the practical advantage of keeping a real aggressive toe setting.
Most experts I've spoken with agree that aggressive toe doesn't really add that much to overall performance to the NSX and unless one is a top driver one won't really extract the most from an agressive toe setting.
That being said, the consensus among the NSX experts I've spoken with is that it is more practical to reduce the toe and take the benefit of longer tire life. I was told a good compromise is to adjust the toe to the least aggressive end of the "acceptable" range the alignment machine provides.
Zero toe is a little extreme, but most of the techs I spoke with say there is nothing really wrong with keeping a zero toe setting if one desires. I've heard tales of rear tires lasting 25,000 miles with a zero toe setting.