In about what % of the time does the guy safeword out?

Of you who are dommes, do you always insist on safewords being available or do you do nonconsent, either generally or because the guy has asked for a no safewords session?

Also, for many dommes, the common safeword used for stop is red. If and when a guy says red, does that mean for you stop what you are doing and talk, stop what you are doing and move to a different activity or stop what you are doing and send the guy home, no matter much time he has paid for?

Or have you done some of these things with some guys and others with others?