This is a very relevant post for me because I've been asking these questions in one form or another for several months. A framework of objective value (FOV) seems to be precluded by physical materialism. However, without it, I cannot see any coherent difference between being happy (or satisfied) because of what is going on in a simulation and what is going on in reality. Since value (that is, our personal, subjective value) isn't tied to any actual objective good in the universe, it doesn't matter to our subjective fulfillment if the universe is modified to be 'better' (with respect to our POV), a simulation we're in is modified to be better, or our preferences are modified.

For example, I asked the question several weeks ago here.

When I began to complain (at length...) that without FOV I felt like I was trapped in a machine carrying out instructions to satisfy preferences I neither care about nor am able to abort, it was recommended that I replace my preference for objective value with a preference for subjective value.

If it is true that the only solution to my problem with the non-existence of an FOV is to change my preference -- and I've already understood that the logical consequence of this is that any kind of preference fulfillment is equivalent to wire-heading -- then I'm simply not going to be very sympathetic to objections to wire-heading based on having preferences for not being wire-headed. It's simply not coherent; there's no difference.