I do have knowledge of a number of people who were multiply grade-skipped/radically accelerated (at least one at around that age), with positive outcomes, but in each case where it was multiple skips at one time, it involved transit through a year of grade-unrestricted learning, often with explicit scaffolding for executive functions and social skills. And for most, it was a series of single grade-skips.

And IQ was never the sole determining factor.

...pronounced like the long vowel and first letter of the alphabet...