In regard to the note that HG & PG kids need more than 1 yr of acceleration barring a 2e issue, maybe but maybe not and I wouldn't worry about that yet when crossing the first skip bridge. My dd is HG but not PG and we've gotten by with the combo of one grade skip, the bd that put her in as young for grade, subject acceleration post-skip, AP & honors courses, and choicing her to a very large high school (around 2,000 kids) so the odds of there being other gifted kids was better, and selecting a school that is very high performing with significantly higher expectations than our assigned school.
I disagree (about PG not needing more than one year acceleration). Being/needing much more advancement is (IMO) the true essence of being profoundly gifted, not getting a random 145 score on a test given on a single occasion (davidson's definition).
In cricket's example above, he/she has a child labelled as HG who required an early school start, a grade skip, subject accelerations and a high performing school in order to accommodate his/her child. A PG child should require even more.