I guess that your application should not use Vector configuration then. The purpose of Vector Spaces is to group axes and define vector moves, the board will calculate each axis parameters in order to achieve the vector move.
If you require different velocity and acceleration per axis you might want to try to make up your own Vector algorithm in which for the eyes of the board you are treating each axis independently, but in your software you are actually grouping them. That is, you will configure each axis by its own, and you can do multi-starts and multi-stops. The Position/Velocity/Acceleration will be calculated by your own algorithm.
Good luck!
Nestor.
Nestor