I believe you may have from my reports the time of 0.0004 to 0.0006 seconds for impact duration. Note that I was reporting the impact duration from different studies with different paramenters (i.e. club, ball, speed...). I have not seen that large a variation in a single study that measured for different clubhead speeds at impact with the same ball.
Also note that even XXX shafts are not infinitely stiff and flexibility that results in a delay between the application of a force at one end and a result at the other end.
It can take up to 1msec [0.001 sec or apx twice the impact duration] for the shock wave [from impact] to travel up a steel shaft (longer for some other materials) and perhaps 20 times longer before the signal has been processed by the golfers brain.
So by the time the grip end of the club is affected by impact the ball is gone.