But string theory doesn't enter into that. Essentially all of the structure spectrum of the CMBR is determined by the fact that energy transport was primarily acoustic.
The Big Bang theory can work with or without string theory.
Do you know why the size of the universe by the inflation model is commonly ignored in popularizations?
For one thing, we only just recently determined that the universe is very, very much larger than the observable Hubble volume. For another, if a writer restricts his comments to our Hubble volume, it is at least possible to talk accurately and provably. And after all, our Hubble volume is quite large enough to blow almost any mind that tries seriously to grasp it.
It's too bad we can't do more experiments more quickly to uncover more of the system behavior of the Big Bang black box. At least it is being done scientifically [with hypothetical components], which would require fewer experiments and would happen sooner, rather than by art, but our set of system components seems to be changing every day. Quantum fluctuation, moderated by neutrinos, inflated to an incomprehensible size, or maybe brane collision, or maybe acoustics in an unknown medium, we need more lab data. Crystallization is as complex.