Scenario: The MSI has different settings for different regions \ groups \ units.
Recommendation: Create one base MSI file and create a transform (.mst )for the region \ group specific installation.
The command line parameter values are ignored and all properties will default to the initial value (which is present in the MSI) during MSI repair.
Use of Transform will solve this problem as the settings will get merged to the base installation.
msiexec.exe /i msiname.msi VARFLIP="True"
If you need to, set the value VARFLIP ="TRUE"
It is advisable to set the value in the transforms rather than running the MSI with command line property value as this value will not be taken care when the MSI goes for repair. It defaults to NULL when the MSI goes for a repair.