As I have said before, the BB is a scattered being in your model, but you yourself might be a scattered being in the BB’s model. So there are not two worlds, a real one and a BB one. There are just two real ones. A better way to think about it might be like special relativity, where each observer has a resting frame and might be moving relative to other ones. In the same way each observer has a reference frame where they are real.
As I have said before, the BB is a scattered being in your model, but you yourself might be a scattered being in the BB’s model. So there are not two worlds, a real one and a BB one. There are just two real ones. A better way to think about it might be like special relativity, where each observer has a resting frame and might be moving relative to other ones. In the same way each observer has a reference frame where they are real.