In the manual reference that"The Mean Squared Error is typically used during manual tuning as a measure of how close the Actual Position, Velocity, Pressure or Force is tracking the Target." and “The Mean Squared Error is the average of the square of the difference. The difference between each sample is squared, and the average of all the differences is the MSE.”

There are two question

1: following error can replace Mean Squared Error . I think following error is better than Mean Squared Error， is it？

2：what average of the square of the difference including ？ Actual Position, Velocity or else for positioning axes？