The OP does not say "let's assume that...", but rather references the multiverse offhandedly, like it's a fact, without even specifying which of the many multiverse models it uses.

As for Tegmark I and II, it is not clear whether the chaotic inflation model will be testable some day. Certainly our current understanding of quantum gravity is woefully insufficient to even make an educated guess as to whether and when and how it can happen. By then I expect that even the multi-level picture itself will be considered naive and outdated.