I agree the Webb will open our eyes in ways the current model is not predicting.
What it will show is the background radiation to be the light of ever further sources, shifted off the visible spectrum. Essentially that we live in an infinite universe and cosmic redshift is an optical effect.
One way light does redshift over distance, is as "packets," because the higher frequencies dissipate faster. Yet the larger implication is that since we are sampling a wave front and not detecting individual photons that traveled billions of lightyears, then the quantization of light is a function of its absorption and detection, not fundamental to the light itself. Which remains wave-like.
It would be one thing if the errors in the current model were subtle, but they are not.
Originally it was assumed these distant sources were simply moving away and it is classic doppler shift. Then it increasingly became apparent that over-all redshift is proportional to distance and since there didn't seem to be anything impeding the light, making it an optical effect, "tired light," the idea became that space itself must be expanding, because "spacetime!"
Essentially that space is some sort of dimensionality, on which light exists like some wavy line, that as it stretches, becomes less wavy.
For one thing, it totally ignores the central premise of GR, that the speed of light remains constant, since if the distance expands, the speed of light would have to increase, in order to remain constant.
Two; That the waviness of light is a function of its motion and detection, not some squiggly line.
So three; Two metrics of space are being derived from the same light. One based on its speed and the other based on its spectrum. The fact is this theory still uses the speed as the denominator, or it would be a tired light theory. As Einstein said, space is what you measure with a ruler and the ruler being used is the speed of light. Any description of this expansion invariably calibrates it in terms of light speed, aka, lightyears. What is the basis of the speed of light, if it is somehow distinct from the space it is crossing?
In which case, what is being measured would have to be increasing distance, in terms of light speed, not "expanding space." So we are back to the problem of appearing as the center of the universe.
Some of us thought this problem would be resolved by the Hubble, but they have managed to either shoehorn all observations into the theory, or ignore them;
https://www.americanscientist.org/article/modern-cosmology-science-or-folktale
There was a time when observation didn't match prediction, the underlaying theory may have been considered falsified, but now enormous patches are added and all is well.
