[fragmede]

Just tie the end of an infinitely long string to the edge of the universe and have it pull on a generator to spin it.

[DoctorOetker]

I would certainly like to see serious critical analysis and calculations of such hypothetical setups by physicists.

Would such a setup slow down the local expansion (action and reaction)?

Since iron is essentially a nuclear ground state, a steel cable being lengthened seems like the least worse mass loss imaginable.