Hello,
It is a bit to late for you to have this answer, however, hopefully will b ethe case for someone else.
Indeed, if you leave the default option, you can not see micrometer unit. But, if you open the workbench and go to Units (in the tool bar), you change the units to Metrics (tonne, mm, s, °C, mA, N, mV). Then, you open SpaceClaim, or modeldesigner, and you go to SpaceClaimOption —> Units and change Length to micrometer. You could even change them to nanometers.
I hope this helps,
You are navigating away from the AIS Discovery experience