Question:
For formatting the survey data to go in to Optisurface, does a normal UTM Zone coordinate need to be trimmed to x digits?

Answer:
New version due out in week handles much bigger numbers including UTM.  Becareful using UTM with Trimble Field Level2 as it uses a different conversion that can be more than 15m off at 1km.  (Search for "coordinate check" in Our Konwledgebase) I recommend surveying with the Trimble FMX if you are going to use the Trimble FMX for machine control because of this issue.