Don't bother tuning.
Stock, it hits 2200/tank or better with an LPR. Tune the LPR until it bounces off your finger. Sweetspot the inline reg, then turn it down til you're at velocity. If, at your sweetspot, velocity is low, turn up your LPR slightly.
Rule of thumb: the more you screw with it, the less awesome it will be.
Again: set the LPR until it's bouncing, set the HPR to velocity via 'sweetspotting'. Keep it simple.