The weighted/unweighted issue isn't that important.
First, each Ivy dissects each application and calculates whatever it wants to calculate (an A in AP human geography may not be given the same cred as an A in AP chem). Second, some schools give honors "As" a 5.0 and AP "As" a 6.0; other schools weigh honors and AP the same - so comparing GPAs isn't comparing apples to apples. Third, and most important, is the rigor of the HS curriculum WHEN COMPARED TO LIKE HIGH SCHOOLS (a kid in a HS offering 16 APs has a higher theoretical GPA potential when compared to a school offering 4 APs). So, a kid is expected to take - and make - virtually straight As in the most rigorous curriculum offered by his HS (the school is looking for kids who have proven that they haven't yet hit their academic ceiling, but did hit the ceiling in their respective HS's).
(I would also note that very few Ivy kids take advantage of claiming college credits for those successful AP scores; the student is generally not ready to skip that introductory class. This creates a strange situation where an intro class in, let's say, physics is populated by kids who got a 5 on their AP physics test as well as kids who didnt take AP physics. A tough time for those who didnt take the AP class.)
IMO, the kid who is sitting 90 with a 34 ACT should absolutely wait for the Ivy timeline; they give up absolutely nothing if they want to get to proball and get every benefit (headstart) of an Ivy (and the benefits are real and long lasting). Moreover, many coaches of power programs will always have room for one more 90mph pitcher who doesnt need to worry about academic eligibility (my son was getting offers and serious interest up until he committed - after his OV - in September senior year).