I will defer further praise for that last point only because now that I am convinced that she is right, the inquiry does not stop but only gets going. As she hints this is not in print in English anywhere (that I too have seen), but in two thousand years it cannot fail to have been previously noticed. No doubt others have indeed noticed it and probably commented - in German or Latin or French. We very likely to find out that this point - which really puts an exclamation point on the argument of the poem - has been withheld from us, and not just (if at all) by Cicero, but in the form of later writers who have seen it but whose work has not come down to us. Detective work is needed!
I don't recall this even in Dewitt, which is saying something, given his classical background and otherwise creativity in interpreting Epicurean texts. I don't recall his direct comment on the issue of the end of the pem so it's possible that he hinted at it in an article somewhere, but surely Emily Austin deserves credit for bringing it front and center.