Below: One of the important additional origine of cosmological redshifts: the increasing Planck length of the vacuum for light passing dark matterm even outside galaxies ( GABHs: Galaxy Anchor Black Holes) see also: https://bigbang-entanglement.blogspot.com/2021/10/dual-quantum-push-gravity.html
https://www.blogger.com/blog/post/edit/21850084/758221747200842627#