Flatpak is a way to layer packages on to of each other, so while gimp official will never package gmic or other plugins, we can package them, serve them as a pixls flatpak repo or submit them to flathub. We can list the gimp flathub as a dependency, so it’ll be installed. It’ll also provide updates, and will be simpler the enduaer for plugins that need to be compiled, like resynthisizer