While that is often an interesting question, it isn't very interesting in this case, because for all J such that J is a Jerf, J demands control over J's brain state.

I think it becomes interesting when one of the Jerfs demands something different from the rest.

Also not really that interesting; I am not saying that J's only demands are control over his brain state, only that J has that demand.

Actually I've spent a lot of time contemplating this sort of thing. One of the things you must be very careful not to do is to give in to the temptation to continuously shift frames every time you arrive at anything resembling an answer to a question. The invitation to "ah, but what if...?" everything may feel all profound & stuff, but it is a path to persistent incomprehension, not understanding, because you can "what if...?" your way to anything, and therefore it has no actual information content.

Sorry, I'm still not following. What exactly do you mean by 'control over his brain state' ?

J is just an abstract concept. The concrete demands come from individual Jerfs which could contradict each other.

I must be missing something.

Perhaps a concrete example would be helpful?

I think you might be missing the point of whether it be ethical, or right, or humane to inflict any form of torturous experience on the conscious copy of a person.

Regardless of the hierarchy of the consciousnesses - if they can still feel pain subjectively, where does the line get drawn as to what is right?

If they can independently think/be sentient then they have value to the universe (potentially) and it would be wrong to murder them.