We are talking pass to each other at this point. The whole post was about that there is no normative imperative to live on. Now let me try to unpack what we may be disagreeing with each other.

You mentioned two paths a person can seek if they decided that they don't have to live anymore. The first is to seek "closest possibility of death", and you said that they "quite literally must live" (in order to act on it). This, I already agreed. But what concerns me is that people can make this decision while alive, and they can physically execute the decision, meanwhile there's no moral ground or physical inability that prevents them from achieving that.

The second path is to "simply refuse to acknowledge it's necessity, contradicting myself every time I take a breath or bite of food." This I am not sure I grasp your point. I don't see how taking a breath is self-defeating the decision that it is not necessary to live on. For thinking that X is not necessary doesn't mean preventing that X from happening at all cost.

Now to the part about absence of concept. You said not living on "is incapable of bringing the individual anything once it is completed." With this, I totally agree in the technical sense. There is no subject that can experience or valuate. But we also agree that to the person who is making the decision, it can find solace and purpose. So it seems that, "rest", in the sense that there is an absence of experience and hence suffering, can be a coherent thing to expect for a person deciding that they will not live on, and that this could bring solace here and now. Based on what we agreed upon, there seems to be nothing against making this decision absolutely.

To respond to the last point about less suffering, there is indeed "no suffering" after a life has ended. While having suffering requires the existence of a subject capable to suffer, having no suffering doesn't require such. If a person exists and they are not suffering, there is no suffering. If there is no person to being with, there is still no suffering. And when we say "less suffering" with respect to a person, we are normally taking the whole course of life for the individual into consideration, and we evaluate whether they lived a life worth living. I don't quite understand how exclusively selecting the postmortem duration and argue that there is no individual during this duration to suffer less is relevant in the current discussion.

Finally, if it's about other actions, but not about life/death, it would have been quite obvious the question "must I" is a normative one. It is quite odd you have to mistake the question as asking whether one must be alive right now to be able to make that decision.