RESOLUTION:
- You can create different options including different user mapping file and save them.
And when you run the migration job you can load the associated options.
However it only works in MNSP designer/console. not for MNSPCMD.exe application yet.
1. Create the options and mapping needed
2. Under Options, click "save as" and give it a name
you can also manage the list by using "Manage Options list" as shown below that same window
3. And when you need to run a job, load the Options needed (under Options)