RPi2 on 720p actually goes up to 46FPS with its display, while RPi3 at 64bit (same used for the Pi4) also goes up to 50 at 720p. I have tried indeed the Pi4 at 64bit and noticed the same, which is super weird ... everything is there but some EGL_ANDROID thing comes up as needed, using the same bin that works perfectly on RPi3 at 64bit. I haven't tries the Pi4 32bit image, but I am sure that works as expected so it might be an upstream kernel gotcha, nothing I can really solve.