Use an environment variable to set the temporary file location.
The location used by Moldflow Insight solvers for temporary files is controlled by the environment variable "MFSYN_TMP" which is set in either /etc/opt/Autodesk/ami20YY-RR for a Workstation setup or in <$INSTALL_ROOT>/mfclient.env for a thin client. The default temporary location is "/tmp". Prior to Moldflow 2018 R3 the environment variable "TMPDIR" was used to set this location.