This is pretty much how our DC's second effective grade skip occurred. We were advocating for an SSA in mathematics for our already-early-entered rising fourth grader, which the school agreed to. On the first day of school, DC came home with an all-fifth grade schedule. (8 yo in fifth grade roster of multi-grade classroom ranging up to 7th graders.) After an additional SSA in math the following year, the net result was also a 10 yo in 7th grade, in algebra I.

Of course, every child and school is different, but ours had a generally positive experience. Supportive factors: small, cozy, nurturing school with multi-grade classrooms and teachers accustomed to multi-level instruction. Caring mix of children in the receiving class.

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