amber
you said what I have been saying for so long the Dom must be aware and not depend on the safe word. I have made that mistake a time or two myself and now I know that I have the power to take her where she won't use the safe word because she is too far gone to know she needs to.
Can't stress enough how that has to the Dom's responsibility and duty to know when things have gone very good but very wrong.
I also preach plan not just the session but the emergency possibility so that when things go wrong you can get her ass out of trouble or begin immediate treatment.