Since in my long career through several airlines I have never heard of variable V1 speeds except for improved climb which changes all the speeds where do you find this information. Also by adding an average of 1 knot to V1 and leaving the other V speeds the same what does that accomplish? It seems we are wasting a lot of bandwith here.
You may find the V1 used quoted on your Runway analysis tables (IRT). The choice is generally made by policy for each runway or for an entire fleet or operation.
The software used to produce the IRTs will have a setting along the lines of:
Where a range of V1s is available choose: Highest, Lowest, Balanced or fixed V1/V2 ratio.
The end user on the line doesn't normally see the choices but the type of V1 chosen should in my view be printed on the IRT for information.