There's some "gray area" with something like that, or most things like that as even with a more specific definition of what it is there will still be people saying that how do we know that any particular tower is actually at that level of congestion at a particular time and that we'd have to rely on Verizon to tell us basically, which means there's still some "gray area" nonetheless.
And, just like pretty much with any plan, there will be some that it works better for (for different reasons) and others that it might not (for different reasons), and others still that it doesn't really make too much of a difference (for different reasons). That part of it is kind of neither here nor there realistically speaking.
