It sounds like you figure you are the torch bearer of sanity.
Boeing is safe (and unambiguously correct) in making the firm statement about passing V1 and lever position/continued takeoff, but making a firm directive upon when a human should make a callout for affecting this purpose is not, nor ever will be, a hard and fast scientific calculation.
We want the pilot flying to know when his option to reject has expired (yes, of course, at and after V1). The only way for that thought to actually hit that pilot's brain in a timely fashion is for the non-flying pilot to get the sound waves in motion toward his ears BEFORE V1 in enough time for his ears to send that signal to his brain and for his brain to have sufficient time to register and recognize that call out. Some small margin before V1 is obviously required to do that to be the most accurate and compliant with the V1 decision.
Boeing takes responsibility for the science of their creations, beyond that, they merely help as much as reasonably possible and within their own lawyers' restrictions against exposure from creating over-reaching and rigid rules in the area of human factors.