Ok I think perhaps our difference in perspective comes down to some of the same issues we have discussed in the past about hypotheticals --- I am willing to entertain them as thought exercises, and some people are less willing to engage in that.
It is easy for me to imagine hypothetical circumstances in which continuing to live would result in overwhelming pain with virtually no offsetting pleasure whatsoever. (The situation of Cassius and Brutus after Philippi being one example. So I would ask - "Do you think Epicurus would say that Cassius made a poor decision in committing suicide rather than handing himself over to Antony's men?")
That's only one example and maybe not even the best. The main issue is that I don't see a bright line saying "hang in there to the very last moment" that would apply to everyone in all situations. I see a theme in Epicurean philosophy of taking charge of things and managing every aspect of your life - and death - as aggressively as possible. How we do that would I think be a personal decision totally context-dependent, and not reducible to a formal test other than where we seem to be ending up, which is something like "never consider suicide lightly and always consider it to be a last resort but know that death is available to you as a relief from pain if in fact you judge the situation makes it the best choice."
Also to close this post it looks to me like much of the reason for the debate at the time was that the Stoics (and others?) seem to have taken a cavalier attitude toward suicide. And of course why not, if you think death is the doorway to paradise? Clearly Epicurus opposed that view, and I would follow Epicurus' original and fundamental position is that death is unconsciousness for eternity, and something that we generally want to postpone as long as possible. However just as in the letter to Menoeceus we don't choose the longest life but the most pleasant, we consider the management of our final moments to be part of the calculus to consider in living the "most pleasant" life.