Seems utterly pointless. And even though they appear to be using fancy vector control (as do Leadshine), it's still a stepper, so the additional steps will have little discernible effect if you have any sort of load torque applied.

To be fair, Leadshine also offer resolution of up to 51200 steps per rev - from a 1000PPR encoder. To achieve the additional resolution, they must be using some form of open loop interpolation. I can't imagine anyone uses these settings unless they are hoping to be a lunchtime legend / YT willy waver.