Hmm. I notice that I am confused, because I think of Libby, even more than the Bells, as the paradigmatic example of a utility maximizer (a real one, not a stupid caricature of one). Aelise is my main support for this interpretation: she's willing to fairly radically self-modify to work with Chelsa, and I don't see a Bell in her position doing the same thing (c.f. Chelise and Belle). The au-sunnydale version of the template literally does a utility calculation!

Given this, and putting aside evils-and-up, and knowing that Chris will prevent her from harm, I find it hard to believe that Libby is so vulnerable to hyperbolic discounting that she values sparing herself a pentagon (for the wish) + a hex (for the test) worth of pain, plus making herself a little kinky (which presumably could be undone with another pentagon), now over even a small chance at an essentially unlimited future supply of at least hexes, probably stars, and a decent chance at literal immortality.

Of course, this means I don't know as much about Libby as I think I do. What part of her character am I getting wrong?