Seems to me that all you are doing is ensuring that the V1 call is completed AND understood by the PF by the time the speed reaches V1 which is entirely as it should be.
I believe the 777 makes an auto call (or at least has an option to do so) for V1 for the same reason, can any 777 drivers comment on when the call is started? I suspect it is about V1 -5kts depending on the rate of acceleration .