The time translation invariance which gives rise to the conservation law is a special case of GR's broader energy-momentum conservation, namely the static one where gravity and such are disregarded altogether as in the Standard Model.
This all ties back to the present crisis of foundations, as string theory and other approaches to reconciling GR with the Standard Model strain at the edges of what Noetherian tools can yield. (see: supersymmetry)
This is an old misunderstanding that dates back to the early stages of GR research and has nothing to do with any current crisis.
...and so you have to pick an appropriate underlying vector field you call time to cancel this out and get back the invariant, throwing a wrench into calculations... as a reply to the post you linked points out. At the end of the day, you haven't demonstrated that it preserves the invariant so much as you've changed the question to find another conserved quantity and called that energy instead. This lines up with my broad observation that we're out of runway for the 20th century's symmetry-reliant problem solving and hence have to be increasingly clever with setups to apply generalizations of them.
I definitely learned something new today, though. To boot, these pseudotensors are tamer than I thought they'd be - I expected calculational hacks with no formal analogues explored only in old papers, but sections on jet bundles is something I'd expect in a differential geometry text. Maybe we'll see progress along these lines in the next couple decades.
Does this violation even ever result in more usable energy rather than less?
Like, red-shifting photons reduces their energy…
I suppose if we wanted to do the opposite, it would be making the contraction of space result in photons being blue-shifted, but uh…
Well, that would result in things getting closer together, and unlike expansion, that seems to run into a limit at some point?
I don’t think the laws of physics as they currently are, are sufficient to support an eternity of life (or civilization). For there to be hope of that, it must be hope of something or someone outside of the laws of physics we inhabit (or are well-approximated as inhabiting).
A new heaven and a new earth.
Not just seem to imply, but they do imply[0]. Does that mean that we can build a machine that generates energy and negentropy forever (e.g. an artificial Sun), thus, we can outlive the heat-death of the rest of the Universe? Yes, absolutely. But there are other existential threats, like the collapse of false-vacuum. In the end, it is not known if we have limited or unlimited time here, but Noether's theorem doesn't answer that.
[0] : https://www.google.com/search?q=general+relativity+and+conse...