I must first say, deflection does nothing beyond belt engagement. All the little bolt does, is control how close the secondary sheaves come together when the sled is stopped (or primary is fully open[disengaged]).
Sorry, you are dead wrong here......
If the clutches start out in a bad ratio ( To high of gear because the belt is low in the driven , then the belt is not deep in the drive clutch and the sled is lazy off the line and most likely rpm is a little low )
Until you let off the throttle and let the driven back shift the belt into a higher part in the driven in relation to the drive belt location compared to where it started from a dead stop.
Dan