I guess it happens. Worst I've been was 1/2x, and it was just once, other times only 1/1x, usually in the single-digit range.
Not saying it wouldn't be useful, but there already is a way to "lock" it, by just getting a T3 (although it doesn't help with looking for T2s). Still, T3 are easy to get and just have to do it once for each zone, then you can kill T2s as much as you want.