I think it's worth pointing out that while the Einstein Field Equations are often quoted as G_ab = 8 pi T_ab infact if you do the general derivation you find its possible to add in a term to the G_ab side which does not alter the conservation equation of G_ab;b = 0. This term is L g_ab, where L is Lambda (no LaTeX support and no charmap due to Linux...) and so the fully general EFEs are G_ab + L g_ab = 8 pi T_ab.

Solving this for a homogeneous and isotropic space-time you end up with the FRW metric which includes L in some way. And infact the inclusion of L is something which Einstein was aware of from the start and we now know from such things as string theory constructions that a space-time with L = 0 is fantastically hard to construct from general principles, you're almost infinitely more likely to have a space where L is not zero.

But observations, initially, said it was and that lead to Einstein's 'Greatest Blunder' by him saying "Fair enough, L=0". More accurate epxeirments now say it isn't but its damn close.

So infact, L-CDM and the BBT are actually in better agreement on theoretical grounds, it was only that in the 30s our experiments said "L is so close to 0 we think it is 0".

Dark matter and the BBT are closely linked too, infact the CMB signature requires dark matter, a material which doesn't interact with photons other than through gravity. Dark matter initially arise to explaiin galaxy rotations but now the CMB is evidence for it too.

If you construct the FRW metric (which is a homework exercise for any 3rd year physicist) then you have terms which are 'normal matter' and dark energy. By the Principle of Totality if these things could be non-zero then you should include them in your analysis to check they aren't just really really small. If you do this and then you consider how the metric says such quantities evolve over time as expansion occurs you get the same results as we see in observations. Considerable work exists in the area of 'inflaton moduli' in supergravity and string theory (my supervisor does precisely this) which aims at building a string theory explaination for how and when inflation occurs (compared to just normal expansion).

So infact the conformity between the theoretical construction of a space with normal matter, dark matter and dark energy matches a lot of the things we see in the universe and is intertwined with the BBT.

You can take into account the effect increasing or decreasing expansion has on redshifting with ease using the FRW metric. It has a scale factor a(t) in it, with the Hubble constant being H(t) = a'(t)/a(t). We now know H isn't really constant but allowing for H'(t) being non-zero is little more than a homework exercise if you've seen how to do the behaviour of the length scale for the H = constant case. Hell, I actually did precisely that for a 3rd year computing project (computing varying redshift effects on quasar emissions) and a bit in my 1st year of a PhD (including inflaton behaviour), it is well within the grasp of anyone competant at PDEs and knows a little about programming in C or Mathematica.

The tiny value of L means that the varying of redshift over time is not going to change results in a huge way and it was the tiny tiny variation in results which made us realise L is non-zero. Yes, you're right to question "Does this change redshift results?" but to then instantly leap to "Since it obviously does I don't trust the results" is flawed as you ignore how much it changes things.

Alpha:
So then it follows that the presence of dark matter effectively has zero effect on redshift. I can see that. But are there other (perhaps not imagined) states that could mimic the data that points us to this dark matter? More specifically, could dark matter/energy be some exotic non-massless aether (sorry ... I do hate that word). I intuit an electrostatic-mesh or sorts that (for lack of an educated word) "carries" inertia and gravity ... I would grant that such a mesh would necessarily have to adhere to observed data.