Once again ( As Usual), Update freezes and then requires an entire redownload

What update today? Perhaps the OP is talking about the NAV data update, but that was a several days ago now. That worked for me, as have previous updates, and only the ~120MB of data was downloaded.

This issue seems rare, and not many users have reported it, but there has to be some common element between those that do get it.

One theory was modifying core files could be detected as missing data, but that was never proven.