What about the preference reversal test? If you weren't constituted so as to age and die, how much would somebody have to give you in order for you to agree to self-modify to age and die?

If you genuinely (and not just as a devil's advocate) would place a very low price on switching in that scenario, then your values are indeed consistent and our criticism on this point might be misguided. If you find yourself reluctant in that hypothetical, though (and most people are), then you have an inconsistency, and you should consider the possibility that you're rationalizing in your thoughts about death.