often times, when doing standing starts myself, i get into the “set” position but then when i take off I flex and shift into a new position. Most likely this is due to my body weight being too far back. Still, I bet it takes at least a tenth of a second from the time i want to start to the time i actually start moving. It might take some practice, but try to find that true start position to eliminate that flex/shift phase.
thats my two cents