Unless the school is unusually pro-skipping I wouldn't even mention a two year skip.
It's a good strategy if you want a one-year skip and the school is anti-skipping. Suggest two years, settle for one.
At our anti-skipping school, you'll immediately get dismissed by administration asking for a two year skip (and they'll probably have a good laugh when you leave). Asking for a one year skip gets placated. I don't know a single case of skipping in our large (700 students) elementary.
Not all schools are the same, but unless there's a very clear history and path for a single year skip, I'd stay away from asking for a double. A double skip also has a higher chance of success taken in two steps.
