I was just adding notes to the checklist I have for what I need to do on my site and got to the one about installing this mod when I had a slight idea regarding the achievements... eventually your user status might get very long if you have loads of achievements, so couldn't you create a new database thing called users_achievements that is generated when a new user signs up (the same way all users database rows are) and the default is set as locked. I actually don't think this would be that difficult so as soon as the film I'm watching is over I'll perhaps go upstairs and try and do it
I'm mostly just talking "out loud" here but this would probably be just a way of keeping achievements separated for those like me with organisation issues lol