@rlkeeney You can backup based on checksums or other attributes aside from modification time. Or use a filesystem like ZFS that allows snapshot-based backups, which makes the whole thing irrelevant.
But regardless, this is why I asked for an option to preserve modification time, not making it the default / sole behavior. I'm sure there are a lot of users that prefer the behavior as-is, or have workflows based around the current behavior like you described. But having an option to preserve timestamps for those of us that prefer that behavior would be appreciated.
