The other (and I think more compelling) problem is that the Other Users content has significant lag, based on cached information; it is anything but real time. So by the time that new flag you propose pops up next to a user's name, they could have already posted that writeup and moved on. The other thing to consider is that being "busy" on PerlMonks entails a lot more activities that just drafting a writeup; you could be voting on considerations in Nodes To Consider, tweaking your various User Settings, sending private /msgs, etc.