Values/desires that arise in human-level practice are probably not terminal. It's possible to introspect on them much further than we are capable of, so it's probable that some of them are wrong and/or irrelevant (their domain of applicability doesn't include the alternative states of affairs that are more valuable, or they have to be reformulated beyond any recognition to remain applicable).
For example, something like well-being of persons is not obviously relevant in more optimal configurations (if it turns out that not having persons is better, or their "well-being" is less important than other considerations), even if it's probably important in the current situation (and for that we only have human desires/intuitions and approval of human introspection). Some variant of that is clearly instrumentally important though, to realize terminal values, whatever they turn out to be. (See also.)
One term for the "really terminal" values is "idealized values".
There's a recent science fiction story that I can't recall the name of, in which the narrator is traveling somewhere via plane, and the security check includes a brain scan for deviance. The narrator is a pedophile. Everyone who sees the results of the scan is horrified--not that he's a pedophile, but that his particular brain abnormality is easily fixed, so that means he's chosen to remain a pedophile. He's closely monitored, so he'll never be able to act on those desires, but he keeps them anyway, because that's part of who he is.
What would you do in his place?
In the language of good old-fashioned AI, his pedophilia is a goal or a terminal value. "Fixing" him means changing or erasing that value. People here sometimes say that a rational agent should never change its terminal values. (If one goal is unobtainable, the agent will simply not pursue that goal.) Why, then, can we imagine the man being tempted to do so? Would it be a failure of rationality?
If the answer is that one terminal value can rationally set a goal to change another terminal value, then either