What about the rules in regards to the WW filing for divorce and maintaining her affair?
There is not a specified rule in regards to her filing for D. In a case such as yours, my suggestion would be to continue using the 37 rules as long as you are under the same roof. As soon as the two of you are under separate roofs, then you go dark.
It is not too late to apply these rules, although we can't guarantee how much impact it may have on any individual, I believe it is a good guideline whenever in doubt as what to do.
It is not about what you feel should work in your M. It is about doing the work that gets the right results. Do what works!