Sorry for the delay, but still no luck. I added your suggested config to the bottom of the retroarch.cfg at /opt/retropie/configs/all/retroarch.cfg and the exit button didn’t work.

But yes if I add my above attached retroarch.cfg to my /opt/retropie/configs/megadrive it does work. The same process seems to work for the NeoGeo one too.

Something it my file seems to make it work, but only when it’s in the /configs/emulator folder.