Framerate independancy in C2 is not as correct as you describe it. Basically you are still limited by the dt value (non trigger events are checked every tick, the every 0.001s can only be checked every ticks, aka every dt seconds) the closest you can get to have a framerate independant is to increase by an amount of dt every tick, that will still only increase it every ticks only, but of the good value.
PS: so you have two limitations: the game can be framerate independant as long as you do not try to have times shorter than dt, and as long as the fps value is superior to 10.