I was wonderin how much difference it would make, currently i dont start doing toe up til about 15m where i stop worrying about gettin out with everyone else. Will it make much a difference if i focus on hitting with the ball of my foot off the first step instead of like the 10th?
If you have to think you are in trouble. Are you sure you don’t naturally dorsiflex anyway? Get some video and check.
TC
Dorsiflexion is just raising your toes up right? I don’t know if I even dorsiflex though. If I do, I can’t tell.
I can only really tell I am if I focus on keeping my toes pointed up.
get some ankle-flex straps they help, you can buy them from gills athletics online
stop thinking
Some what? 
I wouldnt try to dorsi flex out of the blocks. I kind of takes away from my prower out the blocks. u dont see to many pro’s doing it from the start.