Since you're homeschooling (essentially), I would call him what he is (a kindergartener), and allow him to do whatever level of academic work that is appropriate. If the online school won't allow this, I would consider homeschooling independently.
Anyway, my point is that I'd wait to officially advance him until he enters a brick and mortar school and you know what his needs are at that point.
I'd echo Kai's suggestion - although I will add that I have no experience with Connections and I have not homeschooled my own children. There are two children in my dd's 5th grade class who were homeschooled (both until 4th grade) and accelerated when they were very young - one was only subject-accelerated so she's where she would otherwise be in grade now in B&M according to age, and she's doing fine with subject acceleration continuing in math and challenging work in other subjects. The other student is younger-than-grade by two years and is in lower-than-grade level math based on the school's placement testing, and finds most of the classroom work challenging across all subjects. She's told my daughter "I used to feel smart, but now I don't" - which is really not a good situation to be in - she is a smart girl, but she probably would be feeling much better about herself if she'd been subject-accelerated rather than "grade" accelerated in her online schooling.
polarbear
