That's really interesting. I have been reading books by physicists who support the Multiverse theory, and though I'm not completely convinced, the proponents have a good deal of experiential evidence on their side. Those who don't hold to the theory say it's simply an interpretation, though the alternative is to believe that particles can be at two places at the same time. I am currently tending towards a belief in the Multiverse, something I never really accepted before.
If the Multiverse is, in fact, reality, then a Metaego is certainly a possibility. I have wondered how all those alternate selves get along in their respective Universe, how we all relate. At a higher dimensional construct, of course! I hadn't gotten that far in my thinking about it, but it does make sense. Perhaps we do have a Metaself that is an aggregate of all those temporal selves. Entirely possible.
Turn off your mind, relax and float down stream
It is not dying...It is not dying
Lay down all thought; Surrender to the void
It is shining...It is shining...
RealAwareness