Ok, bear with me guys, I don't know if this will make sense or not. Did you ever have one of tose moments when you were thinking about stuff as you were going to sleep, and something occurs to you so you write down and hope it makes sense in the morning.... well this was one of those times.
According to the force/velocity relationship muscles can exert more force concentrically at slow speeds and more force eccentrically at faster speeds.
If hypertrophy is related to amount of tension generated in the muscle, then wouldn't it be most effective to use a tempo that reflects this (fast eccentric slow concentric)?
Problem: Since you can handle more weight eccentrically than concentrically, using normal free-weight exercises, the eccentric portion would be under-loaded.
Solution: Weight releasers or chains/bands with at fast eccentric phase followed by a slow concentric phase.
Slow what do you think. Fast overloaded eccentrics with slow concentrics for hypertrophy?