Isn't this going to persist the getenv() contents in the export file?
- Not, The ExportManager always read file if exist and put in Map, this operation is do in constructor. I put getenv() in Map variables and not in file, the file not is altered, only memory variable.

Think that getValue() should fallback to getenv() if the value is not found in the export file, wdyt?
- Your way really is better! 

This will happen when the export command is issued after the shell boots up!
- Yes, but, is necessary has isLoadSystemEnv as true value in your Settings. You can use getenv or not, it's optional.