Well, creating new realities at will and switching between them is an example of Hub World. And I expect that would indeed be the first thing the new posthumans would go for. But this type of existence is stripped from many restrictions, which in a way make life interesting and give it structure. So I expect some of the posthumans (amongst them - me in the future) to create curated copies of themselves, which would gather entirely new experiences, like Waker's subjectivity. (it's experiences would be reported to some top-level copy)

You see, a Waker doesn't consider waking abandoning everything, the way we do. She doesn't feel abandonment, the same way we don't feel we have abandoned everything and everyone in the dream. She has the perfect awareness of current world and a world to be feeling exactly as real.

One other way to state it - staying in a one reality forever is for a Waker feels like (to us) staying in a dream and never waking up to experience the actual reality.