At this point the new information doesn't really hurt at all. It just is what it is. Just more pieces to a puzzle to get a fuller picture. I have an analytical mind so more information puts it at ease. OM's W is the same way and she's just trying to corroborate different information to see if he's still lying. If WW and I talk, any information I get from OM's W will do the same for me.
I can understand your line of thinking. I was like that for a long time as well. It took me a long time to accept that there are things that Ill likely never know, questions Ill likely never ave the answer to.
I dont really agree that it's more pieces to a puzzle. The puzzle is already finished. Your W had an affair. The details are far less important than the background information. "What did you do" is much less important than "why did you do it". Id highly recommend the TED Talk about infidelity by Esther Perel. To me, you are collecting extra pieces - like trying to complete a 100 piece puzzle with 200 pieces. All that will do, in my opinion, is prolong your healing and make it more difficult.