All the files of the --input dir are copied into the "app" dir, including any file or files with the extension "cfg".
When building an app image jpackage creates one "cfg" file for the main launcher and possible additional "cfg" files for each additional launcher built due to --add-launcher option.

The manifesting problem is that when an app-image with extra "cfg" files is used to create an installer on windows, we look for the <name>.cfg file to determine the name of the application, then create shortcuts using <name>.ico to app <name>.exe.
if we are looking at the wrong <name>.cfg file in the app directory, we will not be able to find corresponding ico or exe and will not create any shortcuts.