ExportFbxVersion: FBX201600 | FBX201400 | FBX201300 | FBX2012 | FBX201100
Unless set in the config file it will default to the 2014 version. If you have older software that has problems importing the FBX file try an older version.
Setting config values from the command line
Any of the above settings in the Open Brush.cfg file can also be specified on the command line (not applicable to Quest users). The format is --Section.Setting <value>. For example: