Static weights haven't mattered for a long time. Balance holes can be used to influence ball roll because they actually change the shape of the core (assuming you go deep enough to hit it). If you just put one in to make the ball weigh without drilling into the core, it does nothing to influence reaction.
Let's face it with common sense, when you are dealing with cores that weigh several pounds by themselves, going over on top weight by a 1/4 ounce is like spitting in Lake Superior and issuing a flash flood warning.