Was the period removed? I remember a few months ago, there would be a `.` after the post age if it was the user's most recent post. Looks like it's not there anymore though.
There are only so many slots available for user preferences before things become much too complicated, and I don't think that one clears the bar. It's much harder to remove these things than to add them. Better not to get on the bad side of that Maxwell demon.
To be honest, I'd take all the options you can throw at me. And a command line to manage them. It's HN after all.
PS. Just hide them behind a karma threshold and a tickbox to acknowledge that they all are ephemeral and can disappear at will. Complications, like in mechanical watches. For people who can appreciate them, to show what's possible :)
