The multiverse in Best's Cosmoline contains infinitely many universes using it's extra 2 dimensions, and a Cyberverse in the center. This cyberverse is also called a multiversal matrix. This cyberverse contains exclusively all cyberspace in the multiverse.
Despite the multiverse being infinite in size, it's filled with infinitely many universes. This is not because the multiverse uses Glitchonicite to let in infinitely many universes, but instead it's higher dimensions.
A universe is like an infinitely thin piece of paper in the 4th dimension. This already allows infinitely many universes in the multiverse, but the multiverse still has another dimension, so that infinite pack of universes in 4D space is still an infinitely thin piece of paper in the 5th dimension.