I don't really understand what you're trying to do. You can't influence your op up chance with what you're describing or not.

Overall my understanding is PEY is the best class to score op ups from, so thats going for you. What's going against you is obviously CX DMs are ahead of you, and according to recent reports here so are CX GOs and even SLs. But on some flights Y is super oversold and J isn't, and they go down and op up everyone and their brother. Anyway, I don't think it's worth obsessing over. Your odds are decent, but admittedly not amazing and just roll with it. Not much you can do.