Thanks for the answer! I'll have to think some more about this. I meant "within one current human".
Hm, interesting. I was more pointing to the current human, as you write. What I was trying to get at was that I would think it would be absurd for someone to accept, say, 50 years of burning of alive before the nerves die off, for any sort of well-being "within one current human" for 50 years. If this is true for the CU as well, it seems she have to account for such an asymmetry by 'extrinsic' means.
Your answer (and the links) definitely made me a lot more uncertain about a bunch of things though!