Well, it took just under three hours for the in game update.
The choppy network continues during game play but isn’t noticeable. (Though it hangs for a long time on loading screens)
Downloading a test file in the Nox browser (512mb) was also choppy but it at least reached normal network speeds. So I think the choppy=ness is the issue, and because Duel Links can’t handle the choppy-ness it has to go extreme slow to not mess up the download. I’ll try some other apps tomorrow and try to get to the bottom of this choppy internet, If only a few users have this problem it most be something silly like a hardware, driver, or windows 10 software error.