Coming back to this thread because we just finished a 6-month production run of fine-blanked transmission plates in 16MnCr5, holding ±0.008mm consistently. Few things I learned that might help:
The V-ring comment above is spot on — we dropped V-ring height from 0.45mm to 0.35mm on the servo and actually got better edge quality. The theory is that the servo's controlled entry speed (we run 3mm/s at contact) gives the V-ring more time to establish the hydrostatic pressure zone. On a flywheel press at 15-20mm/s entry, you need the taller V-ring to compensate for the faster material flow.
Biggest lesson: your fine blanking clearance needs to be tighter on a servo press than on a hydraulic. We started with the standard 0.5% of material thickness and had rollover issues. Dropped to 0.3% and the cut edge went from 85% to 95% clean-shear. I think it's because the servo's constant-velocity stroke doesn't have the pressure fluctuations that hydraulic systems have, so the material shears more cleanly with less clearance.
One gotcha — if you're running CPK studies, make sure you're measuring at thermal equilibrium. Our first 50 parts after cold start always measured 0.005-0.008mm different from steady-state. We now run 100 warm-up cycles before starting any CPK study, and we don't count those parts. Made our CPK jump from 1.5 to 1.8 just by fixing the measurement protocol.