Single Status Update
I thought uncorrectable sector count and other such errors were properties of the drive itself, irrespective of the actual data they contain, but I just experienced something that makes me seriously question that.
I dug out an old drive that was good last time I used it but had been sitting in a closet for years and did a fresh (quick) format, along with enabling bitlocker. It started causing issues so I unplugged it and restarted it a few times, even starting another format and turning it off in the middle of that - all of which easily adding up to enough that I'd expect serious corruption and data loss (if there was any data to lose, which there wasn't), but nothing a format wouldn't fix.
However Crystal Disk Info was reporting errors and saying "caution". This wasn't surprising to me as I figured it had gone bad while sitting around and this was causing the issues that made me do the above things.
I've since started a clean format once again, this time doing the long version, and it's not done yet but Crystal Disk Info no longer reports any errors.
Perhaps the error was caused by my fiddling around? Although that doesn't explain the source of the weirdness to begin with... though I could blame that on Windows (bitlocker). More importantly though, it seems the error has been fixed by formatting. That I did not expect.