@unspeaker retooted just incase anyone understands (I myself dont 😅)
@unspeaker @tiredhorizon
It's probably somewhere under gconf… or dconf… of gsettings, or — whatever new thing they have that apes Windows registry 😆
There is also xdg-mime that you can use to manage file type associations, but again — I'm not sure GNOME considers its DB a priority or relies on something else these days.