Lewis’ conceptualization of many worlds is purely philosophical and not based on a statistical solution to a dogged problem in theoretical physics. But what I like about it is it gives the most degrees of freedom possible (that I’ve seen).
There’s room in it for EVERY theoretical physics’ many worlds interpretation to work, more conceivable situations and combinations, because of their lack of interference.
For example, I think if there is a many worlds model that INCLUDES interaction between universes, in Lewis’ model it would actually be represented by a type of one Universe with the qualities of the interacting multiverse.
Philosophically, it’s breathing room.