Punching time is 60-330ms, depending on what stick you have. I don't know the sequence of operations during a punch to know for sure whether it is possible to have a punch recorded without a beep, but I think you'd run a pretty high risk of punching too fast and not having it recorded at all if you tried to get by without waiting for the beep.
I was looking at a 'how to run a sprint' video, and the guy just seemed to keep moving...
I agree, it would be risky to just go. I'm too much of a worrywart.
And really, I'm not at the state where 2 seconds (even times 18 controls) makes a difference.
... and when I rent a stick, I'm at the 0.33s record time (plus time to beep). Oh well.
I could let you borrow mine which is a newer faster version; might save you a good 2-3 seconds over the course of the race!
Probably should use the time to figure out where to go next!