Yeah I will see what Tire Rack has to say too about a pro-rated set too. I put ECSs on mid-April last year, drove 10k, now two are at 2/32, two are at 4/32. I do really love the tire too, and at $675 for four 235/40/18's (before mounting), I think they are a pretty dang good deal.
They last forever and are a steal. If a tire can last me a full season of daily driving + a full season of tracking (10days) and still have 3-4/43 left they can have my money. They are also incredibly cheap.