Actually, it's the new model that doesn't account for roller wear. In theory, it checks the change in length, just like a ruler. The change in length is a true measure of the change in pitch, but that is due entirely to wear between the pins and inner plates and has nothing to do with the rollers. The old models exaggerated the elongation, by adding the roller wear and elongation. Campy chains don't increase in length nearly as much as most other brands. If the new park tool or a ruler is used to measure the length only, you may find .25% elongation after 6000 miles, but that does not mean that the chain is not worn out. The rollers and side clearance between plates will show extreme wear after this much use and the cassette it was used with will most likely have sprockets that skip with a new chain. Campy recommends a length check between the rollers, that is mostly roller wear and only a small amount of elongation. Both should be measured separately, if you really want to know what part of the chain in the most worn.