Dwain Chambers mentioned that after his squat improoved from 180 to 230kg, he did not have any improovement in his 100m times.
I know that’s not what you were looking for, but I don’t think the squat is all that great.
It is merely a basic strength exercise to keep the body strong because weather / travell / time, don’t allways permit you to train on the track. I can’t rate the squat as being much more than that.
In my opinion: weight lifting only helps those areas where G-force is high. That is, the beginning of the race. (even then, block start practice, plyo’s, sled starts, would be more effective than weights, and a lot more fun.)