If you had access to a scifi-level artificial super intelligence that could simulate anything perfectly at unimaginable speeds, what experiments would you want to run that would be unethical otherwise
I'd totally simulate myself. As far as I'm concerned, a copy of myself is as legitimately "me" as my flesh. There's nothing that makes the simulated @queermunist less real than the one that works for a living making car parts.
I'd upload everyone. I'd also give them something for their trouble, since apparently all religious people and all hardcore atheists hate the sci-fi story I wrote where humanity's descendants resurrect everyone who ever died that was ever part of the Homo genus; the body their heart truly desires would be their VR avatar, though with delicious ironic caveats because if what your heart truly desires is money or power or fame over all other aspects, and that's been detrimental to others, deserves to be trapped as a virtual solid gold statue or somesuch forever for being a selfish fuck.
Basically, what if heaven and hell were not places, but literally whether being your true self truly makes you happy? That hell is if you needed to rethink your shallow, fake or otherwise hollow-feeling lifestyle but didn't do so soon enough and now you're stuck looking and feeling like what you slowly come to hate about yourself or at least who you were when you died.
Like I said, no one ever has to say goodbye ever again.
Punishment, though? I can definitely imagine a digital copy of Elon Musk living 100 lifetimes as different underaged cobalt miners he exploited; ironic punishment with valuable lessons, so when the lesson finally sinks in he can join digital heaven with everyone else.
Hell won't be eternal - just long enough for you to change your ways and feel remorse for what you did.