I am thinking that these would have secondary effect but for accuracy.
1 MPH = 1.47 ft/sec
Average Stride = 6 ft
0.7 secs = 5.8MPH
For every 0.1 sec difference you are talking about 1 MPH in average velo. However once foot strike happens linear velocity is converted into rotational. Also remember these are average numbers in actuality there is a velocity and acceleration curve.
I believe intent to throw hard and hip drive are huge in the velocity equation, so I would work on this first and worry about timing it maybe later.
Actually, I don't time it. I want that momentum as fast as a pitcher of mine can give me, so I just teach quickening it. I'm not even sure I know anyone personally who does time it for training purposes. I was pointing out, that for study purposes, it has been timed and shown that there is a coorelation - the higher velocity pitchers recording quicker times to foot strike.
I also wanted to ask BOH what you mean when you say "hip drive." I think I know, and I have some strong aopinions on that, but don't want to comment without knowing we're talking about the same thing.