20240520 UPDATE: I just ran winupdate on an ancient win10 surface and after the same 643 error two more times, and running through all the available updates, it’s now reporting I’m up to date. yippee.
I guess the latest update finally fixed it, at least on the Surface.

Anyone tried and succeeded? Not too awful plodding through the resizing? Tips to avoid destroying a partition and having to reinstall the os?