Clapper was tested and confirmed to work with V4L2 stateless decoders. Also since latest GTK4 version moved to EGL on Xorg we no longer have the GLX related problems we used to have.
Player window is considered mobile friendly with its transitions and touch/swipes gestures implemented. The only missing part now is preferences window that needs moving to libadwaita. Due to video playback being mobile friendly, mark this app as Purism Mobile compatible which will allow the app to appear on mobile app store and show the app icon in app launcher.