It may last just until you relax about the PFA and get casual about it. You know the saying about giving someone an inch and they will take a mile? He may even be the "good guy" long enough that you dismiss the PFA. But abusers do not just spontaneously change for the better.
It's sort of like the alcohol was for me when I was still drinking. I could sort of "control" it for periods of time when I had a good enough reason, but as soon as the reason was gone I reverted to my default level of drinking. I'm not trying to compare the alcoholism to abuse, but they are the similar in the way that real change requires concerted effort beyond just avoiding the external behaviors for a period of time.