It may be useful to have a game launcher with these features:

• Update functionality for non-package-installs (Windows, macOS?)
• Mod ordering and activation (later, the download and update manager for those)
• Convert script invocation (for initial convert-mod creation and updates)

If needed, it can be extended with some more features, but this should be good for now.

I'd say this should be written in Python and Qt.

It strongly works together with #632 and then has to provide information to the engine about the activated mods when it performs the launch, but how? :)