Hah, that Eclectic Light post got immediately bookmarked in one of my DevonThink libraries!
The part of the post that stuck out to me was this:
Perhaps the worst approach the user could then try is one of the solutions most commonly recommended: turning iCloud off and back on again, as it has no effect on the retry interval, and could trigger further throttling.
Indeed, when I’ve sometimes had iCould sync issues in the past, I’ve done just this (on recommendations from various sites), typically to no avail. Now I know why it failed.
Sort of!