I think a lot of us have settled on HG+ as a "above a certain point" label as categories get so fuzzy and tests are so varied.
Definitely a wide variety of learning styles, not all are academically bent, but rate seems to be a telltale sign.
IQ drift is a bit more mythology as it is measuring across kids an age and putting them on a curve. If one kid's IQ goes down, another kid's must go up in principle.
I think you are at the right school if the teacher gets him, but each year can be a fresh start.
