sigh I remember a family we used to live next to with a son who was my brother’s age (in fact, their birthdays were a week apart). After much handwringing, my parents decided it would be best if my brother started kindergarden a year later than usual. The neighbor’s son (who exhibited the same sort of late-bloomer characteristics) was put in kindergarden that year.
My brother went on to do well when he was in kindergarden and thereafter. The neighbor’s son failed every year. When the school said they wouldn’t pass him, his mother went up there and made a scene so they would give him all D’s and pass him. Her son is basically illiterate now.
If the school had refused to budge on the issue, this entire mess could’ve been sorted out in kindergarden or first grade, and perhaps the boy would be at least functionally literate.