Catching up with you. I haven't read this whole thread, but I do notice something different than when your SO first came back. You seem more insecure in the relationship now and perhaps less confident in yourself. It seems as though you are in a position of vunerability, as everyone that gets in a meaningful relationship must.
Why are you worried about OW or about any potential OW that occurred during separation? Would knowing about other women help you any? I thought you started a fresh relationship and now come equipped with everything you learned during this painful process. Would you even want SO if he chose some immature charity case over you? Remember, with all you have to offer, he can't do better than you. Just be yourself, make yourself happy, be good to SO, and try not to worry so much about the past (easier said than done).
In the end, it's not the years in your life that count. It's the life in your years. Abraham Lincoln
It is hard to fail, but it is worse never to have tried to succeed. Theodore Roosevelt