The wonderment of physicists who want to delve into the metaphysics of the big bang should not even use the word God.
The puzzles that involved inflation, vacuum energy, the CMB, etc., are all part of understanding the mechanism behind the origin of the universe. There is always one last mechanistic question; how did this all happen. The entity behind this should not be called God because the word carries a lot of historical baggage such as association of the Bible, prayer, singing hymns, and God's micromanaging human events.
The fundamental mechanism should also not be called "first cause" or "intelligent design" because of prior religious use. Science should come up with a new word for the fundamental quest to explain the how or why of the universe.