Until those PATs start to look alarming, the school has no idea about or interest in what you mean by 99.8th percentile
And even with alarming results on achievement tests, not all schools will support acceleration. Our international school (British curriculum) does NOT skip, ever. DS5 scored the highest possible on the reception baseline test (given to UK/Australian schools), and acceleration wasn't even mentioned (and I knew better than to bring it up myself).
But to your point, I do think you need to give up/back off/be patient sometimes. My parents didn't push for acceleration for me, so I found elementary dull. Secondary school was much better, and while a grade skip probably would have helped the perfectionism, that got sorted out in college (without major complications).
Hopefully, whether acceleration happens or not, your son will stay happy and growing academically. It's hard to know what it the right course of action.
