Why not? If you call V1 at the speed exactly, then you simply do not stop once the words are spoken.
Anyways, I was trained to announce so that the callout is finished by the time we are passing the last action speed (v1). Guess about 1 sec is needed. Any captain is surely looking at his ASI at that stage, there is little practical benefit in digging deeper.
-7kt would be definitely non-compliance.
AFAIK Lufthansa uses a different call, and I admit to love their thinking. Same time, same use, yet another word. It is one syllable, so the timing becomes irrelevant. It removes ANY ambiguity about the decision/action meaning. They say ........ “
go”.
Vorsprung durch Expertise, there you have it. In that light a “vee-one” call or this discussion is quite 1950s.