You’re misunderstanding the argument. The article you link is about the aestivation hypothesis which is basically the opposite strategy to the “expand as fast as possible” strategy put forth here. The article you linked doesn’t say that some computation _can’t_ be done orders of magnitude more efficiently when the universe is in the degenerate era, it just says that there’s lots of negentropy that you will never get the chance to exploit if you don’t take advantage of it now.
You’re misunderstanding the argument. The article you link is about the aestivation hypothesis which is basically the opposite strategy to the “expand as fast as possible” strategy put forth here. The article you linked doesn’t say that some computation _can’t_ be done orders of magnitude more efficiently when the universe is in the degenerate era, it just says that there’s lots of negentropy that you will never get the chance to exploit if you don’t take advantage of it now.