Ah. I forgot to explain this in the article, but procrastination blocks are effectively "unstructured" in that I can do whatever procrastinatory task I want during them. (If I want to do something productive, though, I break it and take a productive block.) If I'm doing something that I don't want to interrupt to feed the timer, I can use indefinite blocks or long blocks. I haven't found the system exceptionally stressful, but this probably depends a lot on who's using it and why. I suspect I might be a lot less comfortable with it if I hadn't built it.