Can't do that.
No acceleration/deceleration almost certainly means missing steps.
But don't worry about that. The goPos() function takes care of that in the background.
As said, you just need to fill the newPos array with new positions, nothing else.
Or, what I think you want to do,
calculate the newPos array from a stored EEPROM positions array and some new move.
We can't advise you anything until you post your best code attempt.
Leo..