Some of your refutations seem circular or contrived. How would we already have evidence for a local gravity well whose borders extend beyond the milky way? How are we presuming to measure nuclear times in supernovae other than applying known earth rates of decay to trace amounts seen near supernovae?
A gravitational well would have observable consequences for nearby galaxies. It would have observable consequences for light coming in.
We can compare the decay rates on Earth to those observed from light coming from the distant galaxies. If there was a gravitational well of the sort you need, the differences in the rates would be obvious and huge. They aren't.
I'm not stretching words to point out that about one dozen Bible writers, writing across different cultures and time periods, all said the Heavens were (or are!) actively stretched by God long before we were surprised to learn that space is expanding, and rapidly.
The two verses usually pointed to for this are Genesis 1:6-7, Isaiah 40:22, Job 37:18 and Jeremiah 10:12.
Genesis 1:6-7 talks about the firmament, which was an old view that the sky is a solid shell arcing above the Earth. In Genesis, this was supposed to separate the waters above from the waters below. Not exactly a description of an expanding universe, is it?
Isaiah 40:22 talks about spreading the heavens out 'as a curtain' and 'as a tent to dwell in'. Again, this is an image of the firmament that is suppose to separate the heavens above from those below. Again, not at ALL like an expanding universe.
Job 37:18 describes the sky as 'strong' and 'as molten glass'. Again, a description of a *solid* firmament.
Jeremiah 10:12 refers back to the tent analogy.
So, NONE of the texts usually claimed to describe an expanding universe do so. Instead they describe the sky as either a solid or as a 'curtain' or 'tent' spread out above the Earth. THIS is the spreading referred to.