Quasi-static Phase

Could the very early universe have undergone a quasi-static phase with an extremely modified thermodynamics due to the ultra violet modes?
String gas seems to fail!
My natural question would be even if we believe that there was bounce after the crunching phase which led to the so-called Big Bang, why should we believe in having it in a quasi-static phase?
Thermalization seems to be the Achilles heels of non-inflationary models...

I'm so skeptical!