Huh, that's a good idea, to create a benchmark to rescue the concept of suffering from relativism. But it won't work for me. I'm very anti-death, I don't see death as an escape, or as an action at all: I'm here to live, however unpleasant it gets. Death would be no more pleasant, because being dead is not an experience. It can't logically be an improvement.
It logically can be an improvement if experiences can have negative value. I think most people would prefer non-existence to endless torture with no hope of escape.
No, it's not a zero-value experience: it's no experience. Ugh, how do I express this ... in preferences, an experience of some kind is the goal, or at least, my goal. That means death isn't among the options: putting it in there is a category error.