Well, I am afraid that what you write doesn't really clarify anything.
One of the important questions is how Schroeder manages to vary the time on Earth associated with each day, and this doesn't answer it at all
Another is why use another frame of reference when all of the events appear to involve the Earth and when the audience for well over 2000 years had no concept of time dilation.
And unless my understanding of Relativity is flawed we cannot find an inertial frame of reference from which the Big Bang "originated" - there is and can be no such thing.
(And another bit of Genesis 1, I bet Schroeder does not explain is how day and night are created in the first day.)