One way it may be possible to use the scatter on formal testing is in advocacy, especially if the psych is willing to write up some of what he said: it is fairly common for people with EF deficits, and for GT students (and, even more so, for those who are both) to miss easy items (due to lack of attention/engagement), and get more difficult items correct. It's the same phenomenon, essentially, as driving to work instead of your friend's house because you were "on autopilot". The task was too mundane for full mental engagement, which is what led to making a mistake on a very simple task. This happens to everyone, but is amplified with ADHD, because of the EF weaknesses, and in GT, because so many more tasks are easy. If both descriptors apply, it's that much more extreme. The instructional (not pharmacological) solution to this is to program for a very tight match to the zone of proximal development.
As to more testing, I would keep an eye on how he performs in school and life, and keep further testing in your back pocket for if/when you find that he is not compensating efficiently enough on his own. Don't wait too long, though, if you suspect that he is distressed, or developing inaccurate (negative) perceptions of himself. EF is a relatively late-developing skill in many children, and his GT-related asynchrony may exaggerate that, so it could be that, over the next two or three years, he will pick up enough for EF not to be an obstacle. Language processing deficits will become more apparent as passage-level comprehension and extended writing become more significant aspects of formal schooling. It probably won't be much of an issue for a few years yet. Third or fourth grade tends to be one of the first transitions when high-functioning kids with some kind of learning quirk hit a snag.
