My son's keyboarding skills really weren't fluent until the end of 5th/beginning of sixth.
I used to do a lot of scribing for him, and while the part where he dictated and I typed was an accommmodation, I also helped him with grammar, spelling, and arrangement. Why? Because I used to help my older kids with their homework. That part of called just being a parent helping your kid with homework and is no different than helping them figure out how to solve problems in math.
What I did was first just type the words he dictated with no capitalization and no grammar. I did spell the words correctly. Once we'd finished dictation, he would sit with me and go through the piece line by line. If he missed commas, capitalizations, etc., I would go back through and ask him about those and suggest that perhaps that section would need a comma based on such and such rule. I also pointed out words that were commonly misspelled and explained why it was they're instead of there, etc.
For long assignments like multi-page papers, he still uses me as a scribe, but I now make him develop an outline for the paper either on an iPad, his computer or with pencil and paper.
