I think it is worth noting that the discrepancy here is in factor scores, (we aren't looking at an isolated low subtest) so, depending on how the test administration went, I would feel more comfortable looking at these scores and thinking that they might give some real information about possible "bottlenecks" that might make it more difficult for your child to express his gifts.
At a minimum, you should probably ask your tester to calculate and include the GAI in her report and indicate, in accordance with the test publisher's guidelines, that it, not the FSIQ, should be used as the better measure of his true intellectual abilities.
You have noted your child has difficulties with printing - the processing speed subtests include some motor output items that require rapid visual scanning, so if fine motor or visual-motor coordination is an issue, it will often show up as low scores here. It may be worth asking the tester for a referral for an OT evaluation just to rule out any problems, based on the combination of low processing scores and printing difficulties.
If this were my kiddo, I'd ask for additional testing that looked more closely at these two areas to rule out any hidden issues. Working memory problems, for example, usually show up as an issue in everyday life when you encounter situations where you have to hold and retrieve several pieces of unrelated and non-cued or non-meaningful information in your head simultaneously in order to accomplish your tasks. This can look like carelessness, inattention, or boredom. Differentiating between all of these possibilities is important so you can use the right interventions.
