There has to be something wrong with those times, because the shift doesn't actually take 6.38 seconds and the transmission couldn't survive 6.38 second shifts at 100% throttle.

AFAIK, those times are supposed to set the shift time via a PCM calculation that modifies the line pressure to get the transmission to shift in the time specified. In other words, it is to compensate for the transmission wearing and for variations in the line pressure since the PCM doesn't actually know what the line pressure is.