I think the gifted director is trying to read way too much into it. I'm also biased against testing kids who are so young because at that age IQ testing is very unreliable and not stable. It is not stable until mid to late elementary school. So if you test him again in 3 or 4 years his IQ could be 20 points lower or 20 points higher. That is what happened with my DS. He was tested at 3.5 because of developmental delays and his GAI was 106. He was tested again right after a traumatic brain injury at age 6 and his GAI was 133. Everything shifted up about 25 points. On both tests there was a large gap between verbal and non-verbal but neither psych seemed too concerned about it. There were also large variations between sub-tests. On the latest test he scored 18-19 on matrix reasoning and picture concepts and 13 on block design, because it is timed and his fine motor skills are very poor due to developmental coordination disorder.
If your DS was much higher with the block design section than other sections it is probably because he plays with legos a lot and has "practice" compared to other kids who do not. He probably also does have talent in that area and that is why he is interested, but his score may be inflated. My DS did really well on the object assembly section at age 3 because he did a lot of puzzles at that age. Kids who practice puzzles at home will find it easier to do as part of IQ testing. IQ scores can vary depending on how much exposure a person gets. Kids who score high in vocabulary, for instance, are more likely to have well-educated parents who talk and read to them a lot. This probably starts to even out later on since all kids will be exposed to similar vocabulary at school.
If you really want to know his true IQ, I would wait at least 2-3 more years, and then re-test. Even then it may not be fully accurate.
I would not worry too much about visual tracking unless you have some other reason to believe it is a problem.
