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.
We're going to watch him this year and see if a skip to 2nd seems right next year. We feel like we really lucked out with this teacher, so that's a huge help. I confess that having a teacher suggest a skip made it seem more like we should really think about it and also a lot more frightening. We had always kind of assumed it was off the table, though I won't say we didn't talk about it. Ironically, it's his sister who is the big skip advocate for him. (She didn't hear it from us! It's her own idea.)
We also do not have any testing on him yet.