elevated rear foot split squats will help to generate strength and power across legs in a way that allows them to work independently from each other, if each leg improves in strength individually then the combined output can only improve, however if you are looking to improve vert jump then i would place more of an emphasis on explosive plyo movements, than the hypertrophy.
Smaller levels of Hypertrophy will be a natural by-product of plyo training. Standing box jump of 40" wasnt supposed to be bragging ... all im saying is that with my training methods, i improved it from a 24" box.
And in response to why everyone box jumps it is a way of easily quantifying the advice of "Jump"
Rather than just standing in front of a mirror and hurling yourself at the ceiling and hoping for the best. You can measure improvements, you can progress the movement (when it gets easier) without this development ...... then whats the point, seeing the improvements will also let you know exactly what is working and what isnt, that was just a segment of my program which is more aimed at muay thai but fighters want fast and explosive legs more than most.
Anyway it was a bit of free programming feel free to use or ignore the advice as you see fit ...... its a shame all fitness websites just end in flaming when people are just trying to help others improve, Cheers Lloyd