When we are speaking about what to do with the world, which is what formal preference (extrapolated volition) is ultimately about, this is different in character (domain of application) from any heuristics that a human person has for what he personally should be doing. Any human consequentialist is a hopeless dogmatic deontologist in comparison with their personal FAI. Even if we take both views as representations of the same formal object, syntactically they have little in common. We are not comparing what a human will do with what advice that human will give to himself if he knew more. Extrapolated volition is a very different kind of wish, a kind of wish that can't be comprehended by a human, and so no heuristics already in mind will resemble heuristics about that wish.
so no heuristics already in mind will resemble heuristics about that wish
But you seem to have the heuristic that the extrapolated volition of even the most evil human "won't be that bad". Where does that come from?
It’s the year 2045, and Dr. Evil and the Singularity Institute have been in a long and grueling race to be the first to achieve machine intelligence, thereby controlling the course of the Singularity and the fate of the universe. Unfortunately for Dr. Evil, SIAI is ahead in the game. Its Friendly AI is undergoing final testing, and Coherent Extrapolated Volition is scheduled to begin in a week. Dr. Evil learns of this news, but there’s not much he can do, or so it seems. He has succeeded in developing brain scanning and emulation technology, but the emulation speed is still way too slow to be competitive.
There is no way to catch up with SIAI's superior technology in time, but Dr. Evil suddenly realizes that maybe he doesn’t have to. CEV is supposed to give equal weighting to all of humanity, and surely uploads count as human. If he had enough storage space, he could simply upload himself, and then make a trillion copies of the upload. The rest of humanity would end up with less than 1% weight in CEV. Not perfect, but he could live with that. Unfortunately he only has enough storage for a few hundred uploads. What to do…
Ah ha, compression! A trillion identical copies of an object would compress down to be only a little bit larger than one copy. But would CEV count compressed identical copies to be separate individuals? Maybe, maybe not. To be sure, Dr. Evil gives each copy a unique experience before adding it to the giant compressed archive. Since they still share almost all of the same information, a trillion copies, after compression, just manages to fit inside the available space.
Now Dr. Evil sits back and relaxes. Come next week, the Singularity Institute and rest of humanity are in for a rather rude surprise!