For a broad enough definition of "possible", the least convenient possible world is always maximally inconvenient, no matter what your epistemology or morality or decision theory is. Any formalized deductive logic is always going to have true-but-unproveable theorems. Any priors, Occam-like or not, are always going to lead to wildly incorrect posteriors when inducting based on data from a sufficiently perverse universe. Any decision theory is always going to fail against an Omega whose behavior is "see if he's running that decision theory, then punish him accordingly".

Normally that's not the end of the world. There is probably no Omega who hates us, and so we don't have to worry about our Universe being a deceptive design or about an otherwise rational decision-making process being punished because of its rationality.

But when we start answering hypotheticals, then we are potentially talking about deceptively designed universes whose conceptual existence is a deliberate attempt to punish viewpoints not held by the hypothesizer! That doesn't mean that hypotheticals aren't useful tools or shouldn't usually be answered, but it might still be reasonable to keep the possibility of exceptions in mind.