so the minute "jumps" semi-instanteously
To quote from my review of the Grand Chronographe Email which containes the same movement:
"The chronograph minute hand is “semi instantaneous”. It will start moving approximately ½ second before the minute elapses and the hand will stop on the appropriate indicator about ½ second later"
click here to get to the review and scroll down to see the macro pictures of the finished movement.

The release of the Pulsographe will mark the end of the 13-21 movement. Alas, no more :-(
Best, Mike