If your macro integrates an existing SaaS product with a fully-fledged user interface, you can use the full screen dialog to bring your product interface into Confluence. The chrome on the full screen dialog appears as a black header, and maintains the context for the user of being inside Confluence. It also ensures users have a consistent path back to the main Confluence UI.
UI components
Full screen dialog
Recommendations
Do:
Design an 'Open in' action to allow the user to access the full screen dialog.
Use "Back" or "Back to Confluence" to allow users to return to Confluence.
Follow a design style involving white outline and a pixel width stroke.
Don't:
Use labels like "Exit", "Close", "Save and Close", as they may confuse users and conflict with parts of the Confluence UI.
Provide on-boarding for users during editing. If you need to provide on-boarding, do it when users are inserting your macro.