Does not work properly with Finnish keyboard layout. I suppose it's because the AltGr key is technically left control + right alt and that messes with alt+ctrl shortcuts with this extension. If that's the case, then this extension doesn't read the virtual keycodes nor scan codes but the characters that the key presses produce. This hyphothesis is backed by the fact that the ctrl+alt+number shortcuts work on Finnish keyboard if the respecting AltGr+number combination does not produce a character.