It's a question that's too vague to be usefully answered especially on a forum like this.

There's not such thing as "disabled people who can't write well", there's individuals with specific problems and needs.

Maybe there's jessica who lost her right hand and is learning to write with the left who gets extra time. Maybe there's joe who has some form of nerve issue and uses a specialized pen that helps cancel out tremors. Maybe sarah is blind and has an aide who writes it or is allowed to use a keyboard or or or...