Hi Shari,
My thinking is that starting in 3rd is fine, but if the GT notices that he can have a less disruptive day by starting in 4th - I say 'Go For It.' He has been doing most of his subjects in 3rd or higher this year, so moving to 4th might be natural. Perhaps you can list him as a 3rd grader 'assigned to the 4th grade homeroom' so you can keep him in this amazing school longer.
Academically it sounds like things are fine, as they will keep moving him to 'make it fit,' but it seems to me that socially he might have a better chance of enjoyable social interactions if you minimize the disruption to his day.
DS12 got to start the school year with the class he was going to spend the year with, and he really was very grateful for the experience, having skipped a month into 5/6th grade. "Wow, the teachers spend the first few days telling you exactly what they want from you this year - that's great information to have!"
BTW - I think you are unnescessarily scaring yourself by calling this a 3 grade jump. If his academics were at 3rd and 4th grade level this year, and the teachers though he fit in well, then I wouldn't call it a grade skip at all, just a formalization of the process that has already begun. Or have I missed something?
Our family has only dealt with a 'summer birthday + single grade skip' and yes, it's not enough. I've heard amoung some of the Young Scholar Parents that the 'third skip is the charm.'
((shrugs)) either way, if you are willing to stay flexible - you've won.
Best Wishes,
Grinity
