“Science may come up with explanations for the Big Bang involving multiverses etc.”
Any explanation that invokes “multiverses” is, by definition, not science.
“The cosmos may be more than the visible universe, so deepening scientific understanding may happen but will not necessarily disprove an ultimate Creator, but just push the issue out further than the creation of the visible universe.”
Science can never speak about anything other than the observable universe, for anything beyond is outside of the reach of the scientific method and the set boundaries of natural science. Those who would try to force science to address such matters confuse science with philosophy (if you want to be charitable, it would be less charitable, but perhaps more accurate to call it “tautology”).
There is a lot we don’t currently understand about the Big Bang and the universe, for instance the possibility of additional dimensions beyond the four we see, for example. Why dismiss a priori that science through its methods might enable us to understand more of these matters? What Newtonian physicist would have believed Einstein’s theory of relativity or the Heisenberg uncertainty principle? Faith and science are not contradictory, so I feel no qualms if science were to expand our concept of the Cosmos even further beyond the Big Bang.