All that I can say is to trust your gut..... My *gut* told me that I had only uncovered the tip of the iceburg after Dday. As I found more and more info (on my own) about his current (at Dday time) activities....I *knew* that there was NO WAY that he could have been so ass-deep in the cheating shit and that this cheating that I *knew* of was a recent development. He had so much cheating behavior going on at the time that I found out that I would have to have been *clinically brain dead* to assume that it was a *new* development after 15 years of marriage.
It took 2.5 years AFTER Dday for my stbx to *confess* that he had been a cheater for our entire marriage. By that time, we had already bought and moved into a new house (without selling our old one). There is a BIG difference between cheating for a few years and cheating for 20, let me tell ya.
Your post almost seems to be asking if you can *rugsweep* the past behaviors if his current behaviors are lining up with what he *should* be doing NOW.
And IMO, you can't do that....especially if your *gut* is poking at you.
As I said before, ALL of the cards need to be on the table....."Oh, what a tangled web we weave when first we practice to deceive." - Sir Walter Scott
In my effort to be *concise*, I often come off as blunt and harsh. Sorry, don't mean to be offensive.