Nice to hear from you again! And very pleased that you've found homeschooling to be a good solution for you and him.
Your DS's OT eval results do explain why he scored so much lower on the nonverbal portion of the OLSAT than on the verbal section, as that is very much a perceptual reasoning task. In reading over your prior thread, I also notice that his academic history is a familiar one, as I often see something like that in students with a profile that could be described as a nonverbal learning disability. Literacy is a challenge earlier, until decoding is finally mastered to fluency, and the instructional demands become comprehension rather than decoding. Math is often an early strength, but sometimes becomes a later challenge (especially in geometry), as demands change over from arithmetic to higher-level problem solving. (Math may not, of course, have actually followed this trajectory for your child.)
At this age, honestly, you should be able to tell within a relatively short time if OT is going to impact handwriting or other functional skills. With regard to handwriting for function, I would actually focus on assistive technology, such as the one that all of us use to post on this forum.
Long-term, it will be of more value to him to become fluent with keyboarding and speech-to-text than to invest excessive time and effort into Handwriting Without Tears. (Not that this is a bad intervention, by any means!) My personal standard for functional handwriting is being able to sign your name, complete a form, and write a short note (such as of thank-you note length).
It is not a bad idea to see a developmental optometrist (IMO), especially if the OT suspects a vision issue. Obtaining an assessment does not mean you have to follow their treatment advice.
Does he have any other coordination issues? Such as gross motor ones? If so, there might be value in having a PT or neurologist look at him for other coordination disorders (such as DCD-developmental coordination disorder). Sometimes these mimic ADHD symptoms. There's a lot of overlap between DCD, NVLD, and ADHD in terms of presentation (although not necessarily in origins or interventions).
