If you have a choice between living in Sitka and living in New York, isn't that a choice that splits the worlds too? So in one world you'd be living in Sitka and in another world you'd be living in New York. In general, it would seem like "choose X so that I am in this set of worlds and not in that set of worlds" doesn't work--you're always still in the set of worlds where you made the opposite choice.

Even "choose X so as to increase my measure in this set of worlds and decrease my measure in that set of worlds" won't really work. By definition, the whole set of worlds encompasses all choices. You can't choose X so as to affect something about your situation with respect to the worlds. What would that mean anyway? Would there be a meta-set of sets of worlds, and there's a branch of the meta-set where you chose X and increased the measure of part of the set, and another branch of the meta-set where you didn't choose X and didn't increase the measure of the same part?