Watch BR hit 1st base.
Semantics. While the PU needs to be aware of when the BR reaches 1B to determine the effect of the LBR, it is not necessary to see them hit the base. That is the BU responsibility, even from the left side of the field.
I don't understand what you mean. You say that the PU has to be aware...but not necessarily see them hit the base. Obviously the PU needs to know when the BR hits the base because that's when the LBR goes into effect. Is it that you are satisfied with the PU simply seeing the BR in that area? I wasn't implying anything about a missed base appeal.
I guess overall the mechanics are pretty much the same. There is just a bit of different terminology used.