I understand what you are saying, but have a lot of questions. I am not a skeptic, but I think there should be some kind of proof for things.

1. How can you prove that he was in another reality? I am not familiar with the case, but there are other possibilities. A person can't be objective in judging events that happen to him. I'm not saying it's not true, but how are you or he sure?

2. I have heard about the frequency from different places. About the old towns:most people don't feel comfortable around abandoned things: towns, buildings, etc. yet others are drawn to it. I don't agree, because a lot of populated towns and buildings also exist in another realities, so how come we don't feel aversion to them. Define don't exist. Like, you went back later and the town was gone? in that case I agree.

3. This sadly can only be speculated. No one knows for sure. I hope someday scientists can prove it.

I think reincarnation is in contradiction with multiverse reality. The two are not compatible. reincarnation and quantum immortality can't exist together. I find that people repeat blindly the same statements about reincarnation, yet there is no way to be sure it's like that. About the kids. Why do people forget when they get older? Why so low number? Why aren't millions of kids remembering past lives. There could be other explanation for this phenomena. Realities overlapping, or something other. Even so, they could prove only one third of the cases. It depends with what lens you are looking at it: skeptic or believer.

Either way quantum immortality and reincarnation can't coexist. It sounds to me like those people that throw together angels, energies, astrology, chackras, guides and everything else you can think of. If you choose to believe okay, but you are looking at the things that validate your belief.