Here is another way to think of multiverses;

There is no universal model, no one wave. The models break down over infinities and disappear at zero. Everything inbetween is relational.

Consequently there are multitudes of models. Think General Relativity and Quantum Theory. Think of them as different maps of the same territory.

The problem is that if you try to include all the information from the territory into any particular map, any useful signal would be lost back into the noise. Basically whiteout. They break down over infinities.

What if we have two coordinate systems, backed by different timelines, describing the same territory?

Say the Israeli version and the Palestinian version.

Would that be 6 dimensional, 8 dimensional?

The problem is that math is an abstraction of reality, not its foundation.

Epicycles were brilliant math, as a model of our view of the cosmos, but the conclusions drawn, crystalline spheres as physical explanation, were flawed.

General Relativity is brilliant math, but spacetime is the crystalline spheres.

Time is not the linear flow of present moving past to future, that we experience as mobile organisms, with a sequential process of perception in order to navigate, but activity and change turning future to past. Tomorrow becomes yesterday, because the earth turns.

There is no dimension of time, because the past is consumed by the present, to inform and drive it. Causality and conservation of energy. Cause becomes effect.

Different clocks can run at different rates simply because they are separate actions. Think metabolism.

If the premises are off, all the "shut up and calculate" is just so much GIGO.

Think Artificial Intelligence.