Hi Emmanuel, no this is not possible. In FAI we use deboostrap which already installs package with priority required and important. In the config for the cloud images, we use debootstrap --variant=minbase which only install required packages.
The only way to do it using package_config is to write a hook which dynamically creates a package_config file. That's possible. If you need more info about that, just ask me again. -- regards Thomas
