It is all relative to time. One thing not concidered yet is what to do if the servo has not achieved the demand. Do you run the servo faster/slower (velocity), harder/softer rate of change (acceleration & deceleration), longer/shorter (time) or forwards/back (position) to achieve the end target?

I assume you are attempting to modulate the velocity to achieve an end target at xx time whilst keeping the rate of change and max velocity within the set limits.

If you concider a velocity/time graph (trapezoid shape), with velocity as the height of the perpendicular at the current time, then the distance to travel is the area under the graph from the current position. (see graph in post #1)
The math to extract the velocity demand (in QC's / time period), at any given time, according to end target, defined limitations and servo error, is what you are trying to calculate.

Am I helping?