I'd argue that it's reasonable to place a $0 utility on my existence in other Everett branches; while theoretically I know they exist, theoretically there is something beyond the light-barrier at the edge of the visible universe. It's existence is irrelevant, however, since I will never be able to interact with it.

Perhaps a different way of phrasing this - say I had a duplicating machine. I step into Booth B, and then an exact duplicate is created in booths A and C, while the booth B body is vapourized. For reasons of technobabble, the booth can only recreate people, not gold bullion, or tasty filet mignons. I then program the machine to 'dissolve' the booth C version into three vats of the base chemicals which the human body is made up of, through an instantaneous and harmless process. I then sell these chemicals for $50 on ebay. (Anybody with enough geek-points will know that the Star Trek teleporters work on this principle).

Keep in mind that the universe wouldn't have differentiated into two distinct universes, one where I'm alive and one where I'm dead, if I hadn't performed the experiment (technically it would still have differentiated, but the two results would be anthropically identical). Does my existence in another Everett branch have moral significance? Suffering is one thing, but existence? I'm not sure that it does.