My Godson has this. He was a VERY slow developer. Couldn't read reliably until about 14. However, at 20 he is catching up, I would say he is now at the stage of most 16 year olds, cognitively. He did badly at school, and did not enjoy it at all. He got a lot of support from home, and a lot of reassurance that academics were not the most important things in life. No GCSEs as yet - still trying to get functional skills, and I think he will
Outside of academics, he has developed a wide range of hobbies and skills, and had no difficulty landing a high quality tradesman apprenticeship - he worked as a labourer for the firm first, and impressed them with his attention to detail and skills with his hands.
He has had his moments! struggled with depression as a teen, and had a couple of unpleasant outbursts - I would say aggressive, rather than violent.
However, he is one of the most sensible and practical people I know. His emotional intelligence has always been way beyond his years. He is a very skilled cook! and cooks us wonderful meals. He is an animal lover, and has always lavished great care on all his pets. He is kind and thoughtful and understanding and a wonderful human being.
Not all sufferers of NF1 have learning difficulties, your LO might not. My Godson has had few / no difficulties with his actual tumours, they sometimes grow, they have not harmed him in any way. Your LO might have a different experience.
However, this is my experience. HTH
Lots of love to you and your baby xx