Don do you see homeostasis as being a helpful idea in sorting out this conundrum?
I do think "homeostatis" is helpful, but... I've come to understand that the concept of "homeostasis" has been somewhat replaced by "allostasis." Ex.: "Clarifying the Roles of Homeostasis and Allostasis in Physiological Regulation" (2014)
BUT when I talk (colloquially) about "homeostasis," I'm going to say that I mean an awareness of the well functioning of the body and mind accompanied by a state of satisfaction and contentment.
*That* I think is helpful, and what I believe I would call "ataraxia."
One thing I want to emphasize, too, is that I do not think there are only two katastematic pleasures, e.g., ataraxia and aponia; just like I don't think there are only two kinetic pleasures, e.g., khara and euphrosyne. Those are the four pleasures that Epicurus provides as his examples... but there is no way that those are the only four pleasures that Epicurus believed existed.
Little Rocker's point about katastematic pleasures being always there, always available to perception is exactly right (in my opinion). Ataraxia is always available to be sensed (IF you're body and mind are working right with correct attitudes toward the gods and death etc.) BUT, from my perspective, we also always have access to our memories, to our anticipations (in the colloquial sense not the Epicurean canonic sense). That availability to access and/or generate a particular mental state is what I think katastematic pleasures are. They are not dependent on outside circumstances or chance or fortune.