My confusion is that your taking a weightlifting exercise and trying to decide how it will make you jump higher when it doesn't directly measure any jump specific movement... See my remarks about bench press. Jumping high is based on speed off the ground... That's it. Squats involve slowing down before you reach this point. In early November I weighed 225 and squatted 500. Today I weight about 210 and can squat around 440. My jump went from high 30s to mid 40s. Squats simply don't have correlation for most athletes for the question to be meaningful. It's my opinion and experince of most athletes I work with. There are exceptions I'm sure.
That reminds me to accelerate through the top of the squat, even if the bar leaves my back for an inch. I've been forgetting to do that. There isn't much of a reason to slow down at the top! Same thing with the bench press.
Personally squats have had an excellent correlation to my DLRVJ. Squatting ~2.-2.1x my bodyweight, I've had a ~37 DLRVJ at bodyweights of 175lbs, 190lbs, and over 200lbs... I have videos on youtube right now of this, as well as journal entries on this site. People on this site have seen my skinny high school 175lb self tomahawking with two hands, and also my fatty self at 210lbs squatting parallel 405x4 nearly hitting my head on the backboard. More recently, I have another 2-hand tomahawk vid at a weight of 192lbs.
My RVJ has always had a very strong correlation to my squat:bw ratio provided my movement efficiency didn't go to shit. I get that back quickly though (also noted in my journals). It's why I have such a hard on for getting to a 2.25x bw squat right now. It seems due to the way I'm built/structured, increasing my relative strength while maintaining sufficient movement efficiency (read: bball a couple times a week, pepper in some dunks) is the fastest way to increase my RVJ.
I think I went off topic here. Anyway, I want to comment on this:
Jumping high is based on speed off the ground... That's it.
100% correct. Your velocity as soon as your toes come off the ground is what dictates your vert. What I'm interested in knowing is from a purely physics standpoint now, is if 400units of force for 200units of bodyweight accelerates you at the same rate as 300units of force for 150units of bodyweight. I believe the answer is yes. (edit: fwiw this calculator here says so as well
http://www.higher-faster-sports.com/verticaljumpcalculator.html)
Next question to ask is what a ROFD curve would look like for both people. Perhaps your CNS may have a better ROFD curve in the higher bodyweight scenario because it's more accustomed to lifting heavier absolute weights. I know that there are other factors in play, though. Like ones that Raptor mentioned in his post.
