A new development version has been released. Changes in FS-UAE Launcher 2.9.4dev:

• Try to use config from game database when launching with a WHDLoad archive.
• New startup argument –no-auto-detect-game to disable the above feature.
• Save directory based on archive name when launching with an archive.
• Fixed a bug where rating icons could disappear from variants list.
• New option whdload_preload, defaults to 1 (change in behavior).
• More language flags for the status bar.
• New option to toggle close buttons in dialogs.
• New reset to defaults button on settings pages (GUI does not update yet).

Changes in FS-UAE Arcade 2.9.4dev:

• New option arcade_initial_favorites to start with favorites filter.
• New startup argument –favorites to show the favorites list directly.
• Show game lists in FS-UAE Arcade (favorites, etc).
• New option arcade_theme (=blue/red).
• Fixed aspect correction toggle button.

You need to re-run the file scanner (and game scanner) when updating to this version.

Regarding the favorites functionality, there is no UI to add/remove favorites in the the Launcher/Arcade yet. But you can filter by favorites. For now, favorite games can be added/removed at https://openretro.org/user/favorites and the launcher will sync down this list when updating the game database.