Using both Ctrl+Alt to replace AltGr 3rd level function on xorg
I think creating an XKB keyboard type with map[Control+Alt] = Level3; should do it. Credit to William Hatch at https://unix.stackexchange.com/questions/157834/how-to-bind-altgr-to-ctrl-alt
type "Level3withCtrlAlt" {
modifiers = Control+Alt+Shift;
map[None] = Level1;
map[Shift] = Level2;
map[Control+Alt] = Level3;
map[Control+Alt+Shift] = Level4;
};