Which third-party utilities support these? As I said, AFAIK `zip` on my system does not.

I assume the loss of data is the reason we have an error now -- if that wasn't a concern, zipfile could just silently bump the timestamp to 1980.

When the extensions are implemented, `strict_timestamps=False` should *additionally* use the extension, but default should still be to raise the error (to prevent metadata loss when decompressing with older/simpler tools).