Yes - the challenge and benefit of reaching certainty in the rational conclusion here, is something that really deserves emphasis. I remember, way back when, having to put some work into that - having to visualize the bottom line and the degree of correlation across worlds, just to convince myself that standing in front of a closed door and visualizing in detail a knife-wielding maniac on the other side, did not in the slightest affect my correlation across possible worlds with the number of actual knife-wielding maniacs.

You've just got to make the transition to really really knowing that is true.