I did experiments only with simulator as motion controller.
And find that 0.001 step is usable and has error 0.001 on big increments, with 0.01 step on big increments some times error is 0.02.
Anyway counter calculate 1 or 2 steps more or less sometimes, so will move motor on 1-2 microsteps more or less, so accuracy will be +-0.02mm in my case.
Best Wishes.