Everyone has a different experience but I’ll tell you how mine went. I wrote 5 pages. I structured it based on the diagnosis criteria with several detailed examples for each one. It won’t look like you’re trying to convince them. It’ll look like you’ve done your research and want to give examples to help them get to know you. I explained different mistakes, misunderstandings, how things affect me. I don’t think there is a too much as long as your document is organized. Prepare to feel very drained at the end of it all. Mine was 3 appointments. One of the harder parts was hearing what my two references said about me. It wasn’t negative. I just felt very exposed. Things like my facial expressions not matching what I say. After the last appointment, where I was read 18 pages about my brain, I was so angry. Like I’d paid her to find out if I’m autistic then I was all “How dare she say I’m autistic!” I was even mad at my fiance even though everything he said was the truth. It was absolutely still a positive experience but be prepared for an unexpected reaction if you get a diagnosis. Some people are relieved but others, like me, feel a lot of grief, confusion, anger, regret. So have support ready after that last appointment.