You cannot "choose which world to end up in". In all the worlds, people's choices determine outcomes in the same way they would in just one single world. The choice you make here does not have some strange balancing influence on some world elsewhere. There is no causal communication between decoherent worlds. In each world, people's choices control the future of that world, not some other world.

I may misunderstand what is being said. I thank you for correcting me if so. If choice now equals determined future, does that mean choice past equals determined now? And when does any kind of free will enter the picture for us to be making choices at all?