PE: What if this is simply how it is supposed to be (within spec)? Suppose it is actually a problem, how likely is it this could persist through several batches without being corrected?

On a personal note this curve wouldn't bother me as a user. From a printing perspective it is essentially a straight line with some extra contrast in the very high highlight densities. Actually - this is not all that different from Acros.

I guess it just confuses me a little because when TMY-2 was first introduced I remember seeing a few plots comparing it with TMX (I think Sandy King did an article) and the curves seemed quite similar except a slightly longer straight line for TMY-2 (more gradual shoulder for TMX). The curves above, however, are quite different than TMX.