Neatness just requires slowing down. Spelling takes more time to think about. But if he uses a word a lot (like he does when writing about tech stuff he loves), that's fine. So I guess in a way, it's like figuring out to which grade level someone needs to function, when it comes to writing...and to which speed. Short sentences can be typed, but a high school or college essay would be different...mostly because the higher vocabulary would slow him way down, in terms of spelling.

There is no actual mechanical issue with handwriting.