Is there a way to map the LAR file to an XML format?

Issue

Is there a way to map the LAR file to an XML format with roles for content and documents & media?

Unfortunately is not possible adding roles to various content within an existing LAR by editing the XML file within.
Manually editing a LAR file in general isn't recommended as a wrong configuration may corrupt it or it would cause the import to be out of sync with the export, potentially causing issues for future LAR imports.