Couple of comments on that article. First: i wish she had included a cite on where to find this in Aristotle, but I think this true and a crucial observation for Epicureans to understand about the prevailing view that Epicurus faced:
That is why I argue that PD3, and all Epicurean discussion of "absence of pain" as constituting the highest state of pleasure, is really aimed at establishing pleasure as the highest good, not at making the point that modernists allege (they allege that absence of pain is some uniquely desirable special kind of pleasure - a "fancy pleasure" as described in Elayne's article).
In truth, I would argue, PD3 and PD4 are like PD1 and PD2 - they are statements that establish something else and far more important than what may appear to be on the surface.
PD1, if accepted, makes it impossible to believe in the supernatural meddling gods of the majority view.
PD2, if accepted, makes it impossible to believe in life after death and in the threats and rewards of an afterlife of the majority view.
and PD3, if accepted, makes it impossible to accept the argument of Plato and Aristotle that "Pleasure" can not be the highest good.
Again, the point is this: that Plato and Aristotle and others had seemingly proved to the majority's satisfaction that pleasure alone cannot be considered to be the good. From their perspective pleasure has no "limit" - more of it is always better, so it fails to meet the test of "such that no added good could make it any better." Epicurus answers that and provides a proof of its error by pointing out that "the limit of the quantity of pleasure is the absence of pain." This produces the vessel analogy that a vessel (a human life, viewed as the maximum amount of pleasurable experience a single human can feel) can only be filled so far, and once a vessel is filled to the brim, it cannot be filled any further. Thus PD3 is in my view a backhand / roundabout way of saying what you would expect Epicurus to say: "Pleasure is the highest good."
But just as he chose to say "There are no supernatural gods" and "There is no life after death" in a roundabout way, to "inoculate" you against the reverse opinion, he said "Pleasure is the highest good" in a roundabout way, to inoculate you against accepting the specious arguments of Plato and Aristotle and the rest.