[firebot]

2. It's called relativistic MOND. That exists as a category. RelMOND(for short) includes TeVeS, Einstein–Aether variants, BIMOND, and others.

3. I would wager that what we call the CMB is more of a local effect than a big bang remnant.

I lack the karma to downvote, don't blame me. :)

[dnautics]

2. not a physicist but iiuc the relativistic MONDs have been disappointing? but not enough to rule out

[firebot]

They have varying degrees of 'inelegance' or 'complexity.'

But generally they closely conform to Einstein gravity/standard model, as they incorporate relativity.

But that's still the thing. No theory can explain gravity across the spectrum of variables (from micro to macro scales, apparent lack of dark matter in some galaxies, black holes, why galaxies don't fly apart, etc.) We have a dark gravity problem regardless of which theory you like best.