Ultramarina, my DD skipped into first (a 1/2 split in fact) wih hand writing that was mid K at best (very generously). I "hothoused" (or provided OT, depending on perspective) for 10 mins a day at home on school days. 18 months later she's 6 months ahead of grade in handwriting and much more than that in writing. Don't assume a HG child who needs a skip can't brin their deficit up at a speed no-one has ever seen before.
And note that my DDs handwriting issues come from a physical disability that will never be resolved, it should not be physically possible for her to do many of the things she does (write this well, monkey bars, etc), but she's compensating spectacularly well with intellect. So theroretically a child who is simply a bit asynchronous should make at least as much progress, if not more (if well supported).
