Blackman ran a variation of the offense in high school.
There was a reason why the offense executed so well and everybody knew where to line up when he played in the NC State game. Height also plays a role in this offense. You don't have be a runner if you are 6'5 in this offense. See Nick Foles and Trevor Lawrence.
Do not care about Cac Plumlee. Jordan Travis is next man up after Blackman and is the best fit for the offense out of Legendre, Sims and Plumlee. Of course FSU has to get a another QB commit but I think Legendre is better than said other recruits.