One thing that gives me pause: Arenson wants to include "active" pleasures in the katastematic category in part because she fears Epicureans would otherwise lead boring, passive lives. I don't quite get this. Even if all active pleasures (per Sedley) were to be defined as kinetic, that doesn't mean we're supposed to renounce them. An Epicurean's life can be as active as he or she wants it to be, as long as our choices are guided by prudence, courage, moderation, and justice. Contrast two situations
I think she is wrestling with the issues we have been discussing -- she's aware of the argument that katastematic pleasures are somehow superior, but she is not going to accept the definition of katastemtic that equates those pleasures with basically nothing except some kind of ambiguous appreciation, because that would lead to the conclusion that the Epicurean goal is really to DO nothing in life -- and she isn't going to accept that as what Epicurus tought any more than Gosling and Taylor or Nikolsky or Emily Austin did.
I'm not finished yet myself but it appears to me that she's come up with the idea that Katastematic pleasures cannot really be the sensation-free nothingness that some allege, and she's dividing up pleasures into (1) those that respond to some lack or pain or need, and she's calling those kinetic, and (2) those that she's calling "painless" because they do not arise from a pain or lack. That's where she places smelling roses or music or even having sex, I gather (!)
So I'm still processing too, but as far as i can tell she's locked on in the real issue, sees it as a problem, and isn't going to accept it. She's not going to accept the idea that the best pleasure and therefore the supreme good is "katastematic" if that implies something that cannot be sensed. So she's rejecting the common interpretation of katastematic for that reason.
One really significant aspect of her analysis is that she's focusing on constructing something without reference to Cicero because of a combination of his unreliability or the simple confusion he causes.
But I note Robert that you said that you've read chapters 5-8, and I suspect you'll get a different picture when you read her analysis of Plato and Aristotle in the earlier chapters.