Contacting Exes of the N

How does everyone feel about this?

I have contacted an ex of the N once before after an incident of violence, and it really helped me. He started dating me before he left her (which I didn't discover until later), and I think I provided some answers for her that gave her some closure too. There's another ex that I know of that he treated really poorly, and he still tries to rope her in when he has no steady supply. I feel like I might be able to provide some answers for her too, and it might just be good to have someone who has been in my spot with this particular N.

I don't want to seem crazy though, and I don't want it to somehow backfire.

I've seen some mention of other people doing this and it sounded pretty positive in most cases. I'd love to hear what everyone thinks about this.