If I may echo Mutt's thoughts ...
Both Boeing and Airbus have quite useful videos relating to the V1 question. Each sings to the same basic words and music - in the accel-stop limited case if you aren't stopping by V1 then the decision is programmed - you go.
The real world risks of an overrun are manifest. Consider aircraft deterioration, crew surprise (regardless of training and mindset), runway debris contaminants, etc - the risk equation is very definitely skewed to a go decision as the aircraft approaches V1.
The question of the various rule changes is quite irrelevant. The Standards provide reference performance data which will be approximated in the real world to a greater or lesser degree.