I've been having the same issue. The clutch is very sensitive and only works in a very small range of the lever pull. It's supposed to be my wife's bike eventually but she really doesn't like the clutch.
I'm guessing it has to do with the amount of friction between the clutch plates but haven't investigated further.
All the plates and springs in my clutch are within spec but the steel plates have some minor surface rust from sitting for 10 years. Just speculating at this point, but adjusting the factors affecting friction might get the control we'd like. Oil viscosity, spring pressure, and plate friction could all be adjusted.
I'll be looking into it. Maybe someone here has some advice too.