You can find additional information about microstepping in the Software Documentations.
The calculation for the new
STEPS PER MM value is documented right here.
I personally would only use microstepping for Z-axis because its the only one with loud noise.
Edit: I just activated microstepping for Z-axis with 1/4 steps at my farmbot. Maybe even 1/2 steps would be enough.
I used the following calculations (as seen in links above) to adjust the settings:
Steps per mm: 200 x 4 / 8 = 100
Encoder scaling: 100 x 200 x4 /500 = 160 <-NOTE: I’m using encoders with 500cpr. For original Farmbot use 360 instead of 500, which would make a scaling of 222.
My experience: totally worth it. Movements are much more silent and smooth.