Not sure how many home runs he hit that were 400-440ft. If they all went 10% further then they would be warning track shots. Interesting exercise....a lot of variables.
And sometimes we just get this ( the universe unfolds as it should).....
I recall that they calculated 10% more distance from 3% increase in bat speed. Sounds high but because the batter has faster reaction time, gets better wood on the ball etc. the effects are huge.
Well bat speed shouldnt increase the further a player gets out of his prime years (see Barry Bonds). We have pitch velocity and homerun distance
plus factor in bat weight and factor in some coefficients.....some tall foreheads can give you batspeed.