I have installed fooyin with Flatpak and set it as the default application (KDE Plasma Wayland) for audio files. However, fooyin is now visible in all "Open with! context menus of all audio, video and even image aned office files. Pretty pointless and also kind of annoying. In the fooyin settings there is an option to select what fooyin should be applied to. Here I only specified mp3;flac;wave, but this has no effect on the problem. Even an installation from the AUR did not change anything.