Statesman, why are you guys still screwing around trying to make a fundamentally broken concept work? You've known (or should've known) from day one that SR can't be balanced the way it is implemented, because it's either too good vs minions and LTs or it's too bad against bosses.
I and others suggested a simple fix in the first few weeks the game was out and it still appears to be the best solution:
Make SR give a flat dodge chance in addition to the regular "miss" chance that any other character would have. If a fully slotted SR scrapper has a 66% dodge chance, then that's exactly how much the power is reducing the number of debuffs and damage he's taking. By 66%. So if you decide that the balancing point is 40% or 30% or 10% or 80%, that's where you set the bar at and you leave it alone.
It's easy to implement, it's easy for players to understand, it solves most of the problems with SR, and it just makes more sense for what the power pool is supposed to represent.
Is there any particular reason why you can't go with the best solution, when it also happens to be the simplest and easiest solution?