You said “The best way to avoid it is if you are taking finasteride and have significant eD, then stop the medications before it goes on too long.” That is not an effective risk management approach to avoiding post finasteride syndrome. Once a patient decides to take the drug, they should be aware that they are taking on a risk that they may permanently develop post finasteride syndrome. Your post creates the impression that they have the ability to minimize their damage once they start taking the drug which is not true.
I can only go by the experience of a small handful of doctors in the field who are honorable which probably represent experience with well over 50,000 patients combined together. We all stop the finasteride if the ED can’t be addressed by reduced dosages. In our experience of 50,000+ patients, we have never seen PFS in our practice.