ESC is easy to press when you want to get out of the XP. But I think it’s almost a little too easy. If someone wants to have a keyboard/mouse connected to a kiosk for some reason, it’s almost too obvious to have it as the exit button for the XP. A user could press it by accident, or out of habit.
Any other key combo would help reduce un wanted exits. I should note that I haven’t actually had an issue with this because we normally don’t connect a keyboard to our displays. But my opinion is that it’s a little too easy. (Also disabling Alt+F4 as an exit would be nice too)