[Just go Play]

As I understand it for acceleration ms is the time that it takes to fully apply the new voltage value. This is documented as a method to control possible overloading of the power capacitors due to under voltage.

So during hard acceleration if using a small ms value there are larger spikes in amperage as compared to using a higher ms value.

This may also have a similar effect to setting punch control on an MM controller but I have not played with it enough to confirm this.