In Qt 6.9, we have a new CMake property QT_ANDROID_ICON that can set the icon directly in the manifest without having to manage a custom one. To go a step further, it would be good to be able to provide the path to the icons folder directly, for example:

set_target_properties(...
    QT_ANDROID_ICON "@drawable/ic_launcher" "${path-to-drawable-dir}"
)

Or this way

set_target_properties(...
    QT_ANDROID_ICON "@drawable/ic_launcher"
    QT_ANDROID_DRAWABLES_DIR "${path-to-drawables-dir}"
)

This would then use the drawable directory provided without having to be under QT_ANDROID_PACKAGE_SOURCE_DIR or without the need to specify that latter value.

It would also open the possibility to let the deployment tool configure the icons based off a single image and prepare the Android drawables structure, the same way Qt Creator Manifest Editor does it.