So... I'm curious why this never happened? It would be super useful, and I doubt it'd be that hard to include? Seems sort of silly that the sidebar includes things like hobo and smithness, but doesn't include a counter that, while admittedly not as important as turns, is certainly comparable in terms of function?
I agree with kain (two years ago...), it would make sense for it to be under Adv:, and either say -- if your stone was unbroken, or just not show it, since you probably don't care in that case. But definitely below adv, because that's sort of what it is. It's not a modifier, it's a counter of availability.