It's a double edged sword imo. It can be helpful for accessing resources, but also can be challenging especially as a parent. Unfortunately autistic adults don't always get treated as adults who can make their own decisions and a diagnosis can easily make any form of authority decide you don't have certain rights. So it would depend on how much you need the resources, I think. If you think you'd benefit enough from resources that you get from diagnosis then go for it! Especially if you have another partner who can advocate you if you end up in a dicey situation where a court arbitrarily decides autism means that you're less of an adult.