using Variable for Output File Path

I currenty ran into some troubles using greenshot.

We are trying to change some settings to roll them out in our company.
Each user should be able to save screenshots using greenshot to their specific user path.

Path: \\SERVER_home\${USERNAME}.DOMAIN\Dokumente\Eigene Bilder

The path is set in the .ini configuration file. And testing shows that the ${USERNAME} global variable is correctly translated to the current user.
However, when a screenshot is made the default save location is still going to the Desktop instead of the user’s pictures folder.

Testing using a username directly in the path shows positive results, but that of course is static and not what we want.

Because we still have set a path to …/Desktop it seems to use this as sort of a fallback, because greenshot doesn’t seem to accept the global environment variable.

Is there something we’re missing or are global variable just not supported ?