I completely agree with SA's Sobriety Definition but the "... includes progressive victory over lust" part is not easy to measure. If it was as simple as the "acts" that follow lust (i.e. "acting out"), it would be much easier.
But from my own experience, and from years of listening to other SA's share, I'd have less sobriety and I'd hear others having less sobriety if progressive victory over lust wasn't part of the definition. I think that would be true because I wouldn't have broken through into true recovery without recognizing that if there is to be any sobriety for me, it requires that my surrender is at the level of lust, not just at the level of my acting out behaviors.
For me, acting out is the result that follows my use of my drug of choice: lust. By the time I'm acting out physically, I've already been "drinking". I've already been using. I've already been getting high on lust. And for me, someone who has fully embraced the clear fact that I am a sexaholic, once I'm high on lust, acting out simply follows. That is unless there is some external force that intervenes to stop me.
My sobriety date is set at the last time I looked at porn. It was a clear and conscious choice to do so. I did not surrender my lust. I did not surrender my resentment (which was the trigger that initiated the whole thing). I knew exactly what I could have done instead of resenting and lusting and ultimately turning to porn. But I did it anyway. The only thing that stopped me from continuing to act out was another person breaking into the process that was already in motion (which they didn't know they had done). Otherwise, sex with self was going to happen. I am powerless over lust; that is just what I do when I am not living in a state of surrender to God and refusing to surrender to Him in the moments of temptation and disturbance.
So for me, looking at porn is a clear indication that I am not sober. And that is why I don't spend any time struggling with the desire to look at porn. I simply surrender each passing thought that has its source in my sexaholic mind, whether that be the temptation to look at porn, or to engage in some fantasy or memory, or to take "that look" at that person, or whatever. Surrender, and then surrender again. And God does for me what I can't do for myself.
In summary, for us surrender is the change in attitude of the inner person that makes life possible. It is the great beginning, the insignia and watchword of our program. And no amount of knowledge about surrender can make it a fact until we simply give up, let go, and let God. When we surrender our "freedom," we become truly free. (SAWB p.82)