Update:

We had our son tested at our local Sylvan Center.

They said that they have an elementary writing program that begins at a second grade level. (DS reads at at least a 5th grade level) So we had him evaluated.

Long story short: DS tested in the lower levels for writing in the second grade (elementary writing) test. In the consultation, they seemed unable to understand that we didn't want him pushed to write "essays", but were there to help him with his handwriting and spacing. They said they were going to put together an individual program based on his age, but I didn't see that. My husband and I definitely felt as if this would be detrimental to his learning to write without anxiety. Perhaps our perception was erroneous or only central to our particular center, but I don't think Sylvan understands our needs.

We decided not to push this and are hoping this coming school year at a blended-grade charter will make the difference in his writing.